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The introduction of trifluoromethyl groups into organic molecules is of paramount importance in modern synthetic chemistry and medicinal chemistry. While methods for constructing C(sp2)−CF3 bonds have been well established, the advancement of practical and comprehensive approaches for forming C(sp3)−CF3 bonds remains considerably restricted. In this work, we describe an efficient and site‐specific deaminative trifluoromethylation reaction of aliphatic primary amines to afford the corresponding alkyl trifluoromethyl compounds. The reaction proceeds at room temperature with readily accessible N‐anomeric amide (Levin's reagent) and bench‐stable bpyCu(CF3)3 (Grushin's reagent, bpy=2,2′‐bipyridine) under blue light. The protocol features mild reaction conditions, good functional group tolerance, and moderate to good yields. Remarkably, the method can be applied to the direct, late‐stage trifluoromethylation of natural products and bioactive molecules. Experimental mechanistic studies were conducted, and a radical mechanism is proposed, wherein the dual roles of Grushin's reagent have been elucidated. [ABSTRACT FROM AUTHOR]

A method for electrophilic sulfenylation by organophosphorus‐catalyzed deoxygenative O‐atom transfer from sulfonyl chlorides is reported. This C−S bond‐forming reaction is catalyzed by a readily available small‐ring phosphine (phosphetane) in conjunction with a hydrosilane terminal reductant to afford a general entry to sulfenyl electrophiles, including valuable trifluoromethyl, perfluoroalkyl, and heteroaryl derivatives that are otherwise difficult to access. Mechanistic investigations indicate that the twofold deoxygenation of the sulfonyl substrate proceeds by the intervention of an off‐cycle resting state thiophosphonium ion. The catalytic method represents an operationally simple protocol using a stable phosphine oxide as a precatalyst and exhibits broad functional‐group tolerance. Oat field: A method for electrophilic sulfenylation by organophosphorus‐catalyzed deoxygenative O‐atom transfer (OAT) from sulfonyl chlorides is reported. This C−S bond‐forming reaction is catalyzed by 1 (phosphetane) in conjunction with a hydrosilane terminal reductant to afford sulfenyl electrophiles, including valuable trifluoromethyl, perfluoroalkyl, and heteroaryl derivatives. [ABSTRACT FROM AUTHOR]

Demonstrated herein is the construction of trifluoromethylated quaternary carbon centers by an asymmetric radical transformation. Enantioenriched trifluoromethylated oxindoles were accessed using a hypervalent iodine‐based trifluoromethyl transfer reagent in combination with a magnesium Lewis acid catalyst and PyBOX‐type ligands to achieve up to 99 % ee and excellent chemical yields. Mechanistic studies were performed by experimental and computational methods and suggest a single‐electron transfer induced SN2‐type mechanism. This example is thereby the first report on the construction of enantioenriched trifluoromethylated carbon centers using hypervalent iodine‐based reagents proceeding through such a reaction pathway. Taming the CF3 radical: A unique single‐electron transfer (SET) induced SN2‐type reaction enables the construction of enantioenriched trifluoromethylated oxindoles using a hypervalent iodine‐based trifluoromethyl transfer reagent. A combination of magnesium Lewis acid catalysis and PyBOX‐type ligands successfully tames the highly reactive CF3 radical to achieve excellent enantioselectivities. [ABSTRACT FROM AUTHOR]

An intermolecular C(sp3)−H amination reaction is reported that is promoted by internal oxidants and occurs via a C=N bond formation step. This intermolecular C(sp3)−H amination reaction of trifluoromethyl ketones and aryldiazonium tetrafluoroborates affords various valuable trifluoroacetylated hydrazones in high yields with excellent E/Z selectivities. The salient features of this reaction type is that it is free of metal, catalyst, directing groups, and azides, and that it can be carried out under mild conditions, is operationally simple and efficient, gram‐scalable, and it tolerates various functional groups. Remarkably, an ectoparasites‐controlling agent was smoothly synthesized on a gram scale using our method. Aryldiazonium tetrafluoroborates served as the aminating reagents as well as an internal oxidant. An inside job: An intermolecular C(sp3)−H amination reaction is reported that is promoted by internal oxidants and is realized under mild conditions. Trifluoroacetylated hydrazones that are generated upon C=N bond formation are further transformed into various useful compounds decorated with a trifluoromethyl group. [ABSTRACT FROM AUTHOR]

A simple trifluoromethoxylation method enables non‐directed functionalization of C−H bonds on a range of substrates, providing access to aryl trifluoromethyl ethers. This light‐driven process is distinctly different from conventional procedures and occurs through an OCF3 radical mechanism mediated by a photoredox catalyst, which triggers an N−O bond fragmentation. The pyridinium‐based trifluoromethoxylation reagent is bench‐stable and provides access to synthetic diversity in lead compounds in an operationally simple manner. N‐O problem: A bench‐stable pyridinium reagent transfers the elusive trifluoromethoxyl radical to a variety of arenes, including a selection of biorelevant compounds. By sidestepping limitations of traditional OCF3 sources, this approach enables late‐stage diversification by direct C−H functionalization in a mechanistically unique fashion. [ABSTRACT FROM AUTHOR]

Abstract: The first visible‐light‐mediated synthesis of trifluoromethylselenolated arenes under metal‐free conditions is reported. The use of an organic photocatalyst enables the trifluoromethylselenolation of arene diazonium salts using the shelf‐stable reagent trifluoromethyl tolueneselenosulfonate at room temperature. The reaction does not require the presence of any additives and shows high functional‐group tolerance, covering a very broad range of starting materials. Mechanistic investigations, including EPR spectroscopy, luminescence investigations, and cyclic voltammetry allow rationalization of the reaction mechanism. [ABSTRACT FROM AUTHOR]

Abstract: The first transition‐metal‐free, site‐specific umpolung trifluoromethylthiolation of tertiary alkyl ethers has been developed, achieving the challenging tertiary C(sp3)–SCF3 coupling under redox‐neutral conditions. The synergism of organophotocatalyst 4CzIPN and BINOL‐based phosphorothiols can site‐selectively cleave tertiary sp3 C(sp3)–O ether bonds in complex molecules initiated by a polarity‐matching hydrogen‐atom‐transfer (HAT) event. The incorporation of several competing benzylic and methine C(sp3)−H bonds in alkyl ethers has little influence on the regioselectivity. Selective difluoromethylthiolation of C−O bonds has also been achieved. This represents not only an important step forward in trifluoromethylthiolation but also a promising means for site‐selective C−O bond functionalization of unsymmetrical tertiary alkyl ethers. [ABSTRACT FROM AUTHOR]

Abstract: The first catalytic enantioselective γ‐boryl substitution of CF3‐substituted alkenes is reported. A series of CF3‐substituted alkenes was treated with a diboron reagent in the presence of a copper(I)/Josiphos catalyst to afford the corresponding optically active γ,γ‐gem‐difluoroallylboronates in high enantioselectivity. The thus obtained products could be readily converted into the corresponding difluoromethylene‐containing homoallylic alcohols using highly stereospecific allylation reactions. [ABSTRACT FROM AUTHOR]

Abstract: While acid fluorides can readily be made from widely available or biomass‐feedstock‐derived carboxylic acids, their use as functional groups in metal‐catalyzed cross‐coupling reactions is rare. This report presents the first demonstration of Pd‐catalyzed decarbonylative functionalization of acid fluorides to yield trifluoromethyl arenes (ArCF3). The strategy relies on a Pd/Xantphos catalytic system and the supply of fluoride for transmetalation through intramolecular redistribution to the the Pd center. This strategy eliminated the need for exogenous and detrimental fluoride additives and allows Xantphos to be used in catalytic trifluoromethylations for the first time. Our experimental and computational mechanistic data support a sequence in which transmetalation by R3SiCF3 occurs prior to decarbonylation. [ABSTRACT FROM AUTHOR]

Abstract: A fluoroform‐derived borazine CF3− transfer reagent is used to effect rapid nucleophilic reactions in the absence of additives, within minutes at 25 °C. Inorganic electrophiles spanning seven groups of the periodic table can be trifluoromethylated in high yield, including transition metals used for catalytic trifluoromethylation. Organic electrophiles included (hetero)arenes, enabling C−H and C−X trifluoromethylation reactions. Mechanistic analysis supports a dissociative mechanism for CF3− transfer, and cation modification afforded a reagent with enhanced stability. [ABSTRACT FROM AUTHOR]

Abstract: Corrole and sapphyrin with the smallest meso‐substituents reported so far were prepared in a one‐pot synthesis that relies on a non‐aldehydic precursor for introducing CF3 groups. The substantial amounts of products obtained by this facile pathway allowed for the full characterization of 5,10,15‐tris(trifluoromethyl)corrole, the access to a variety of stable chelates thereof and investigations that disclose the unique structural and chemical properties induced by the CF3 substituents. The novel 5,10,15,20‐tetra(trifluoromethyl)sapphyrin undergoes only single protonation, which according to its crystal structure is stabilized by favorable non‐bonding F/H interaction between the meso‐CF3 and the inverted pyrrolic NH. [ABSTRACT FROM AUTHOR]

The first example of a direct dehydroxytrifluoromethoxylation of alcohols has been developed. This method generated an alkyl fluoroformate in situ from alcohols, followed by nucleophilic trifluoromethoxylation with trifluoromethyl arylsulfonate (TFMS) as the trifluoromethoxylation reagent. The reaction is operationally simple and scalable, and it proceeds under mild reaction conditions to provide access to a wide range of trifluoromethyl ethers from alcohols. In addition, this method is suitable for the late-stage trifluoromethoxylation of complex small molecules. [ABSTRACT FROM AUTHOR]

Functionalization reactions of the refrigerants HFO-1234yf (2,3,3,3-tetrafluoropropene) and HFO-1234ze (1,3,3,3-tetrafluoropropene) were developed. The selectivity and reactivity towards CF3 groups of C−F activation reactions can be controlled by employing either a germane or a silane as the hydrogen source. Unique transformations were designed to accomplish consecutive hydrogermylation and C−F activation steps. This allowed for an unprecedented transformation of an olefinic C−F bond into a C−H bond by heterogeneous catalysis. These reactions are catalyzed by nanoscopic aluminum chlorofluoride (ACF) under very mild conditions. [ABSTRACT FROM AUTHOR]

A catalytic intermolecular allylic C−H trifluoromethoxylation reaction of alkenes has been developed based on the use of a palladium catalyst, CsOCF3 as the trifluoromethoxide source, and benzoquinone as the oxidant. This reaction provides an efficient route for directly accessing allylic trifluoromethoxy derivatives with excellent regioselectivities from terminal alkenes via an allylic C−H bond activation process. [ABSTRACT FROM AUTHOR]

Tris[tetrafluoro-4-(trifluoromethyl)phenyl]borane (BTolF) was prepared by treating boron tribromide with tetrameric F3CC6F4-CuI. The F3CC6F4-CuI was generated from F3CC6F4MgBr and copper(I) bromide. Lewis acidities of BTolF evaluated by the Gutmann-Beckett method and calculated fluoride-ion affinities are 9 and 10 %, respectively, higher than that of tris(pentafluorophenyl)borane (BCF) and even higher than that of SbF5. The molecular structures of BTolF and BCF were determined by gas-phase electron diffraction, that of BTolF also by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

One long-standing issue in directed C−H functionalization is that either nitrogen or sulfur atoms present in heterocyclic substrates may bind preferentially to a transition-metal catalyst rather than to the desired directing group. This competitive binding has largely hindered the application of C−H functionalization in late-stage heterocycle drug discovery. Reported here is the use of an oxazoline-based directing group capable of overriding the poisoning effect of a wide range of heterocycle substrates. The potential use of this directing group in pharmaceutical drug discovery is illustrated by diversification of Telmisartan (an antagonist for the angiotensin II receptor) through copper-mediated C−H amination, hydroxylation, thiolation, arylation, and trifluoromethylation. [ABSTRACT FROM AUTHOR]

Disclosed herein is a novel, redox-neutral protocol for the visible-light-induced radical alkynylation of unactivated olefins. The intramolecular migration of an alkynyl group, by cleaving an inert C−C σ bond, is realized for the first time. A wide range of synthetically useful trifluoroethylated linear alkynes are readily obtained under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Trifluoromethylthiolation by sulfuration of difluorocarbene with elemental sulfur is described for the first time, which overrides long-standing trifluoromethyl anion-based theory. Mechanistic elucidation reveals an unprecedented chemical process for the formation of thiocarbonyl fluoride and also enables transition-metal-mediated trifluoromethylthiolation and [18F]trifluoromethylthiolation of α-bromo carbonyl compounds with broad substrate scope and compatibility. [ABSTRACT FROM AUTHOR]

In the presence of trifluoromethylsulfonium reagents, boronate complexes derived from 2-lithio furan and non-racemic secondary and tertiary alkyl or aryl boronic esters undergo deborylative three-component coupling to give the corresponding 2,5-disubstituted furans with excellent levels of enantiospecificity. The process proceeds via the reaction of boronate complexes with a trifluoromethyl radical, which triggers 1,2-metallate rearrangement upon single-electron oxidation. Alternative electrophiles can also be used in place of trifluoromethylsulfonium reagents to effect similar three-component coupling reactions. [ABSTRACT FROM AUTHOR]

We report an efficient oxidative radical desulfur-fragmentation and reconstruction of enol triflates for the synthesis of α-CF3 ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3 radical from the triflyl group of enol triflate and subsequent addition of the CF3 radical to another enol triflate form the desired α-CF3 ketones. This method provides a new approach to α-CF3 ketones, featuring the utilization of catalytic amount of oxidants, broad substrate scope, and potential to control the regioselectivity. [ABSTRACT FROM AUTHOR]

A novel method for the conversion of vinyl triflates into α-trifluoromethylated ketones in the absence of external trifluoromethyl sources is described. This process accomplishes an efficient migration of the trifluoromethyl group of the triflate to the α-position in the ketone through a radical process. The reaction proceeds by the addition of a trifluoromethyl radical to the vinyl triflate and subsequent fragmentation of the trifluoromethane sulfonyl radical. Based on this reaction, a one-pot two-step procedure for the trifluoromethylation of ketones was developed. The method presented herein also allows the transfer of perfluoroalkyl groups from vinyl perfluoroalkanesulfonates, which are readily accessible from alkynes and perfluoroalkanesulfonic acids. [ABSTRACT FROM AUTHOR]

Reported herein is the one-pot synthesis of trifluoromethylated amines at room temperature using the bench-stable (Me4N)SCF3 reagent and AgF. The method is rapid, operationally simple and highly selective. It proceeds via a formal umpolung reaction of the SCF3 with the amine, giving quantitative formation of thiocarbamoyl fluoride intermediates within minutes that can readily be transformed to N-CF3. The mildness and high functional group tolerance render the method highly attractive for the late-stage introduction of trifluoromethyl groups on amines, as demonstrated herein for a range of pharmaceutically relevant drug molecules. [ABSTRACT FROM AUTHOR]

Upon activation under superacid conditions, functionalized tailor-made N-SCF3 sulfenamides served as reagents for the trifluoromethylthiolation of aromatic amines. This method has a broad substrate scope and can be used for the late-stage functionalization of complex molecules such as alkaloids or steroids. Mechanistic studies based on in situ low-temperature NMR spectroscopy revealed the involvement of dicationic superelectrophilic intermediates. [ABSTRACT FROM AUTHOR]

A novel phosphine-catalyzed, highly enantioselective umpolung addition of trifluoromethyl ketimines to Morita-Baylis-Hillman carbonates was developed and it provides facile access to optically active trifluoromethyl amines with a chiral tertiary stereocenter under mild reaction conditions. The salient features of this reaction include general substrate scope, mild reaction conditions, good yields, high enantioselectivity, ease of scale-up to gram scale, and further transformations of the products. [ABSTRACT FROM AUTHOR]

A continuous-flow method for the regioselective arylation of fluoroarenes and fluoropyridines has been developed. The telescoped procedure reported here consists of a three-step metalation, zincation, and Negishi cross-coupling sequence, providing efficient access to a variety of functionalized 2-fluorobiaryl products. Precise temperature control of the metalation step, made possible by continuous-flow technology, allowed for the efficient preparation of the arylated products in high yields and short residence times. Additionally, several examples of the regioselective arylation of benzotrifluoride derivatives are also provided. [ABSTRACT FROM AUTHOR]

The synthesis of mono-, di-, and trifluoromethyl aryl ethers by fluorodecarboxylation of the corresponding carboxylic acids is reported. AgF2 induces decarboxylation of aryloxydifluoroacetic acids, and AgF, either generated in situ or added separately, serves as a source of fluorine to generate the fluorodecarboxylation products. The addition of 2,6-difluoropyridine increased the reactivity of AgF2, thereby increasing the range of functional groups and electronic properties of the aryl groups that are tolerated. The reaction conditions used for the formation of trifluoromethyl aryl ethers also served to form difluoromethyl and monofluoromethyl aryl ethers. [ABSTRACT FROM AUTHOR]

Heterobimetallic molecular complexes or strictly alternating metallated polymers are obtained by a click reaction between mononuclear metal complexes (secondary building units, SBUs) bearing NHCs functionalized with either p-azidophenyl or p-ethynylphenyl wingtips. With a copper-NHC complex as SBU the formation of molecular or polymeric compounds did not require any additives as the copper complex catalyzes the click reaction. Transmetallation from heterobimetallic Cu/Ag derivatives to Cu/Pd derivatives was achieved. The linker between the SBUs (flexible or rigid) influences the catalytic activity of the heterobimetallic compounds. The polymer with alternating copper-NHC and silver-NHC units and a flexible methylene-triazole bridge between them shows the highest activity in the catalytic alkynylation of trifluoromethyl ketones to give fluorinated propargylic alcohols. [ABSTRACT FROM AUTHOR]

Reported herein is an asymmetric [3+2] cycloaddition reaction of azomethine ylides with β-trifluoromethyl β,β-disubstituted enones, a reaction which is enabled by a Ming-Phos-derived copper(I) catalyst (Ming-Phos=chiral sulfinamide monophosphines, Figure [ABSTRACT FROM AUTHOR]

Abstracts of articles related to chemistry are presented including DNA nanotechnology, trifluoromethylthiolation, and halogenases.

Enantioselective trifluoromethylthiolation, especially of alkenes, is a challenging task. In this work, we have developed an efficient approach for enantioselective trifluoromethylthiolating lactonization by designing an indane-based bifunctional chiral sulfide catalyst and a shelf-stable electrophilic SCF3 reagent. The desired products were formed with diastereoselectivities of >99:1 and good to excellent enantioselectivities. The transformation represents the first enantioselective trifluoromethylthiolation of alkenes and the first enantioselective trifluoromethylthiolation that is enabled by a catalyst with a Lewis basic sulfur center. [ABSTRACT FROM AUTHOR]

The asymmetric addition of terminal ynamides to trifluoromethyl ketones with a readily available chiral zinc catalyst gives CF3-substituted tertiary propargylic alcohols in up to 99 % yield and 96 % ee. The exclusion of organozinc additives and base as well as the general synthetic utility of the products are key features of this reaction. The value of the β-hydroxy-β-trifluoromethyl ynamides is exemplified by selective transformations to chiral Z- and E-enamides, an amide, and N,O-ketene acetals. The highly regioselective hydration, stereoselective reduction, and hydroacyloxylation reactions proceed with high yields and without erosion of the ee value of the parent β-hydroxy ynamides. [ABSTRACT FROM AUTHOR]

Combining single electron transfer between a donor substrate and a catalyst-activated acceptor substrate with a stereocontrolled radical-radical recombination enables the visible-light-driven catalytic enantio- and diastereoselective synthesis of 1,2-amino alcohols from trifluoromethyl ketones and tertiary amines. With a chiral iridium complex acting as both a Lewis acid and a photoredox catalyst, enantioselectivities of up to 99% ee were achieved. A quantum yield of <1 supports the proposed catalytic cycle in which at least one photon is needed for each asymmetric C-C bond formation mediated by single electron transfer. [ABSTRACT FROM AUTHOR]

The aza-Michael addition reaction is a vital transformation for the synthesis of functionalized chiral amines. Despite intensive research, enantioselective aza-Michael reactions with alkyl amines as the nitrogen donor have not been successful. We report the use of chiral N-heterocyclic carbenes (NHCs) as noncovalent organocatalysts to promote a highly selective aza-Michael reaction between primary alkyl amines and β-trifluoromethyl β-aryl nitroolefins. In contrast to classical conjugate-addition reactions, a strategy of HOMOraising activation was used. Chiral trifluoromethylated amines were synthesized in high yield (up to 99%) with excellent enantioselectivity (up to 98% ee). [ABSTRACT FROM AUTHOR]

First evidence for the existence of free trifluoromethyl anion CF3- has been obtained. The 3D-caged potassium cation in [K(crypt-222)]+ is inaccessible to CF3-, thus rendering it uncoordinated ("naked"). Ionic [K(crypt-222)]+ CF3- has been characterized by single-crystal X-ray diffraction, solution NMR spectroscopy, DFT calculations, and reactivity toward electrophiles. [ABSTRACT FROM AUTHOR]

A novel method for convenient access to CF3-containing azirines has been developed, and involves a copper-catalyzed trifluoromethylazidation of alkynes and a photocatalyzed rearrangement. Both terminal and internal alkynes are compatible with the mild reaction conditions, thus delivering the CF3-containing azirines in moderate to good yields. The azirines can be converted into various CF3-substituted aziridines. [ABSTRACT FROM AUTHOR]

The direct and chemoselective N-transacylation of peracetylated chitooligosaccharides (COSs), readily obtained from chitin, to give per- N-trifluoroacetyl derivatives offers an attractive route to size-defined COSs and derived glycoconjugates. It involves the use of various acceptor building blocks and trifluoromethyl oxazoline dimer donors prepared with efficiency and highly reactive in 1,2- trans glycosylation reactions. This method was applied to the preparation of the important symbiotic glycolipids which are highly active on plants and to the TMG-chitotriomycin, a potent and specific inhibitor of insect, fungal, and bacterial N-acetylglucosaminidases. [ABSTRACT FROM AUTHOR]

An asymmetric unactivated alkene/CH bond difunctionalization reaction for the concomitant construction of CCF3 and CO bonds was realized by using a Cu/Brønsted acid cooperative catalytic system, thus providing facile access to valuable chiral CF3-containing N,O-aminals with excellent regio-, chemo-, and enantioselectivity. Mechanistic studies revealed that this reaction may proceed by an unprecedented 1,5-hydride shift involving activation of unactivated alkenes and a radical trifluoromethylation to initiate subsequent enantioselective functionalization of CH bonds. Control experiments also suggested that chiral Brønsted acid plays multiple roles and not only controls the stereoselectivity but also increases the reaction rate through activation of Togni's reagent. [ABSTRACT FROM AUTHOR]

The development of multicomponent reactions for indole synthesis is demanding and has hardly been explored. The present study describes the development of a novel multicomponent, cascade approach for indole synthesis. Various substituted indole derivatives were obtained from simple reagents, such as unfunctionalized alkenes, diazonium salts, and sodium triflinate, by using an established straightforward and regioselective method. The method is based on the radical trifluoromethylation of alkenes as an entry into Fischer indole synthesis. Besides indole synthesis, the application of the multicomponent cascade reaction to the synthesis of pyrazoles and pyridazinones is described. [ABSTRACT FROM AUTHOR]

The trifluoromethanide anion is the postulated key intermediate in nucleophilic trifluoromethylation reactions. However, for more than six decades, the trifluoromethanide anion was widely believed to exist only as a short-lived transient species in the condensed phase. It has now been prepared in bulk for the first time in THF solution. The trifluoromethanide anion with the [K(18-crown-6)]+ cation was unequivocally characterized by low-temperature 19F and 13C NMR spectroscopy. Its intermediacy in nucleophilic trifluoromethylation reactions was directly evident by its reaction chemistry with various electrophilic substrates. Variable-temperature NMR spectroscopy, along with quantum mechanical calculations, support the persistence of the trifluoromethanide anion. [ABSTRACT FROM AUTHOR]

The direct ortho-trifluoromethylation of arenes, including heteroarenes, with TMSCF3 has been accomplished by a copper(II)-promoted C-H activation reaction which completes within 30 minutes. Mechanistic investigations are consistent with the involvement of C-H activation, rather than a simple electrophilic aromatic substitution (SEAr), as the key step. [ABSTRACT FROM AUTHOR]

The first catalytic asymmetric carboannulation with allylsilanes is presented. The enantioselective [3+2] annulation is catalyzed using a scandium(III)/indapybox complex with tetrakis-[3,5-bis(trifluoromethyl)phenyl]-borate (BArF) to enhance catalytic activity and control stereoselectivity. Functionalized cyclopentanes containing a quaternary carbon center are derived from alkylidene oxindole, coumarin, and malonate substrates with high stereoselectivity. The enantioselective 1,4-conjugate addition and enantioselective lactone formation (by trapping of the β-silyl carbocation) is also described. [ABSTRACT FROM AUTHOR]

We present a practical trifluoromethyl-directed Wacker-type oxidation of internal alkenes that enables rapid access to β-trifluoromethyl-substituted ketones. Allylic trifluoromethyl-substituted alkenes bearing a wide range of functional groups can be oxidized in high yield and regioselectivity. The distance dependence of the regioselectivity was established by systematic variation of the number of methylene units between the double bond and the trifluoromethyl group. The regioselectivity enforced by traditional directing groups could even be reversed by introduction of a competing trifluoromethyl group. Besides being a new powerful synthetic method to prepare fluorinated molecules, this work directly probes the role of inductive effects on nucleopalladation events. [ABSTRACT FROM AUTHOR]

The nickel-mediated [3+2] cycloaddition of 2-trifluoromethyl-1-alkenes with alkynes afforded fluorine-containing multi-substituted cyclopentadienes in a regioselective manner. This reaction involves the consecutive two CF bond cleavage of a trifluoromethyl or a pentafluoroethyl group through β-fluorine elimination. [ABSTRACT FROM AUTHOR]

A silver-catalyzed decarboxylative trifluoromethylthiolation of secondary and tertiary carboxylic acids under mild conditions tolerates a wide range of functional groups. The reaction was dramatically accelerated by its performance in an aqueous emulsion, which was formed by the addition of sodium dodecyl sulfate to water. It was proposed that the radical, which was generated from the silver-catalyzed decarboxylation in the 'oil-in-water' droplets, could easily react with the trifluoromethylthiolating reagent to form the product. [ABSTRACT FROM AUTHOR]

The fluorine-containing organic motif is becoming privileged in pharmaceuticals, agrochemicals, and functional materials, owing to its unique properties such as electron-withdrawing character, metabolic stability, and lipophilicity. Described herein is the PhI(OAc)2-mediated radical trifluoromethylation of vinyl azides with Me3SiCF3 to efficiently generate α-trifluoromethyl azines. The resulting α-trifluoromethyl azines were successfully transformed to valuable fluorine-containing molecules such as α-trifluoromethyl ketones, β-trifluoromethyl amines, 5-fluoropyrazoles, and trifluoroethyl isoquinolines. [ABSTRACT FROM AUTHOR]

Radical paths: The title reaction of olefins with NaSO2CF3 and N‐hydroxy‐N‐phenylacetamide at room temperature is described for the first time (see scheme). This reaction provides a practical and convenient route to a series of trifluoromethylated alcohols bearing a wide range of functional groups. [ABSTRACT FROM AUTHOR]

RBF3K is a chemist's BFF: A metal‐free synthetic route to unprecedented organoboron compounds bearing an α‐trifluoromethyl substituent, employing a variety of trifluoroborate (RBF3K) starting materials, is reported. These substrates represent the first isolated α‐trifluoromethylated alkylboron building blocks, and these reagents lead to a variety of useful bench‐stable, synthetic intermediates. Pin=pinacol. [ABSTRACT FROM AUTHOR]

A chiral Lewis base or a phase‐transfer catalyst (PTC) can mediate the highly enantioselective trifluoromethylthiolation of β‐ketoesters with the previously developed SCF3 reagent (see scheme). Reactions of indanone‐derived β‐ketoesters occurred with high yield and excellent enantioselectivity with quinine as catalyst. Reactions of tetralone‐ or 1‐benzosuberone‐derived β‐ketoesters occurred with moderate to good enantioselectivity with a quinine‐derived PTC. [ABSTRACT FROM AUTHOR]

Metal‐free: The first metal‐free aryltrifluoromethylation of activated alkenes has been developed. With this method, trifluoromethylated isoquinolinediones, spirobicycles, oxindoles, and α‐aryl‐β‐trifluoromethylamides were obtained with high control of the regioselectivity. [ABSTRACT FROM AUTHOR]