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A new class of palladium nanoparticles encapsulated in an organic crystalline salt matrix Pd@F2 (A‐2) was developed. Matrix A‐2 was readily prepared by mixing an aqueous solution of the tetrasodium salt of tetraphenylmethane‐tetrasulfonate and the PdCl4 salt of protonated tetrakis(4‐aminophenyl)under hydrogen in water. Matrix A‐2 contained 17–20 % of palladium and was not pyrophoric. The average size of the palladium metal particles was 7 nm. Matrix A‐2 could be used as an efficient heterogeneous catalyst for the reduction of acetylene derivatives and had activity similar to that of Pd/C. The catalyst could be recovered and reused several times with just one four‐hundredth of the palladium leaching after the first cycle. The reduction of diphenylacetylene could be selectively stopped at the cis‐stilbene stage after one equivalent of hydrogen was absorbed. The same selective conversion could also be accomplished with terminal acetylenes. Matrix A‐2 reduced aldehyde and epoxide groups very slowly which allowed the selective reduction of the acetylenes in the presence of aldehydes. This behavior contrasts with that of Pd/C which reduces both aldehyde and acetylene groups simultaneously. A model, suggesting the selective imbedding of the aldehyde groups in the organic F2 matrix of A‐2, isolating them from the palladium active sites, explains the observed phenomena. [ABSTRACT FROM AUTHOR]

The efficient chemo‐, regio‐ and stereoselective formation of saturated carbon‐carbon fragment is the critical challenge of organic synthesis; therefore, developing new methods for formation of these bonds is paramount. The rising interest for reductive aldol‐type reactions is conditioned by its versatile applications, allowing the efficient formation of carbon‐carbon bonds. The review aims to highlight the advantages and disadvantage of reductive aldol‐type reactions to total synthesis of pharmaceutical substances in order to summarize knowledge and encourage further investigation of the field. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of chiral diene rhodium catalysts is introduced. The readily available racemic tetrafluorobenzobarrelene complexes [(R2‐TFB)RhCl]2 were separated into two enantiomers via selective coordination of one of them with the auxiliary S‐salicyl‐oxazoline ligand. One of the resulting chiral complexes with an exceptionally bulky diene ligand [(R,R‐iPr2‐TFB)RhCl]2 was an efficient catalyst for the asymmetric insertion of diazoesters into B−H and Si−H bonds giving the functionalized organoboranes and silanes with high yields (79–97 %) and enantiomeric purity (87–98 % ee). The stereoselectivity of separation via auxiliary ligand and that of the catalytic reaction was predicted by DFT calculations. [ABSTRACT FROM AUTHOR]

On the basis of the 1,2,3,4‐tetrahydrofluorenyl ligand, a simple approach was developed to new effective rhodium catalysts for the construction of C−C and C−N bonds. The halide compounds [(η5‐tetrahydrofluorenyl)RhX2]2 (2 a: X=Br; 2 b: X=I) were synthesized by treatment of the bis(ethylene) derivative (η5‐tetrahydrofluorenyl)Rh(C2H4)2 (1 a) with halogens. An analogous reaction of the cyclooctadiene complex (η5‐tetrahydrofluorenyl)Rh(cod) (1 b) with I2 is complicated by the side formation of [(cod)RhI]2. The reaction of 2 b with 2,2′‐bipyridyl leads to cation [(η5‐tetrahydrofluorenyl)Rh(2,2′‐bipyridyl)I]+ (3). The halide abstraction from 2 a,b with thallium or silver salts allowed us to prepare sandwich compounds with incoming cyclopentadienyl, dicarbollide and mesityleneligands [(η5‐tetrahydrofluorenyl)RhCp]+ (4), (η5‐tetrahydrofluorenyl)Rh(η‐7,8‐C2B9H11) (5), and [(η5‐tetrahydrofluorenyl)Rh(η‐mesitylene)]2+ (6). The structures of 1 b, 2 b ⋅ 2I2, 3PF6, 4TlI4, 5, and [(cod)RhI]2 were determined by X‐ray diffraction. Compounds 2 a,b efficiently catalyze the oxidative coupling of benzoic acids with alkynes to selectively give isocoumarins or naphthalenes, depending on the reaction temperature. Moreover, they showed moderate catalytic activity in other annulations of alkynes with aromatic compounds (such as benzamide, acetanilide, etc.) which proceed through CH activation. Compound 2 b also effectively catalyzes the reductive amination of aldehydes and ketones in the presence of carbon monoxide and water via water‐gas shift reaction, giving amines in high yields (67–99 %). [ABSTRACT FROM AUTHOR]

Tertiary amines represent a key class of organic molecules with multiple industrial, synthetic, and analytical applications. The focus of this review is on different approaches towards the synthesis of the C3 and C3V symmetrical tertiary amines. Generally, symmetrical tertiary amines can be prepared via N-alkylation with alkyl halides and alcohols, reductive amination, desamination, hydroamination of olefins, and different kinds of C-N cross-coupling reactions. All reactions leading to the titled structures are discussed, and the advantages and disadvantages of each method are provided. [ABSTRACT FROM AUTHOR]

The method of direct reductive amination of camphor and fenchone was proposed. The most effective reducing agent is iron carbonyl. No ligands or solvents are needed. The stereochemistry of the corresponding products was determined by HMBC, HSQC, and NOESY spectra. The limitations of the method were shown. The reaction of camphor with primary amines led to exclusively exo product, while the reaction of fenchone led to exclusively endo product. The reaction of camphor with cyclic secondary amines led to the mixture of endo and exo isomers. [ABSTRACT FROM AUTHOR]

Carbon monoxide used to have a limited number of applications in organic chemistry, but it gradually increases its role as a mild and selective reducing agent. It can be applied for the carbon–heteroatom single bond formation via the reductive addition of hydrogen-containing nucleophiles to carbonyl compounds. In this paper, rhodium-catalyzed reductive esterification is described, and a comparative study of the rhodium and ruthenium catalysis in the reductive addition reactions is provided. Rhodium performs better on highly nucleophilic substrates and ruthenium is better for compounds with less nucleophilicity. [ABSTRACT FROM AUTHOR]

The effect of donor (D)–acceptor (A) alignment on the materials electronic structure was probed for the first time using novel purely organic porous crystalline materials with covalently bound two‐ and three‐dimensional acceptors. The first studies towards estimation of charge transfer rates as a function of acceptor stacking are in line with the experimentally observed drastic, eight‐fold conductivity enhancement. The first evaluation of redox behavior of buckyball‐ or tetracyanoquinodimethane‐integrated crystalline was conducted. In parallel with tailoring the D‐A alignment responsible for "static" changes in materials properties, an external stimulus was applied for "dynamic" control of the electronic profiles. Overall, the presented D–A strategic design, with stimuli‐controlled electronic behavior, redox activity, and modularity could be used as a blueprint for the development of electroactive and conductive multidimensional and multifunctional crystalline porous materials. [ABSTRACT FROM AUTHOR]

An efficient method for preparation of secondary amides from primary amides and aldehydes using rhodium on carbon matrix as catalyst was developed. The method does not require any external hydrogen source and carbon monoxide is used as a reducing agent. The most active rhodium catalysts were characterized by BET, TEM and XPS techniques. Unexpectedly, it was found that heterogeneous rhodium on carbon matrix works as precatalyst for homogenous active species due to leaching of rhodium to the solution. Various secondary amides were synthesized and checked for antifungal activity. 4‐Methoxy‐N‐(4‐methoxybenzyl)benzamide demonstrated promising activity against Rhizoctonia Solani. [ABSTRACT FROM AUTHOR]

Common and non‐toxic aldehydes are proposed as reagents for alkylation of ketones instead of carcinogenic alkyl halides. The developed reductive alkylation reaction proceeds in the presence of the commercially available ruthenium catalyst [(cymene)RuCl2]2 (as low as 250 ppm) and carbon monoxide as the reducing agent. The reaction works well for a broad substrate scope, including aromatic and aliphatic aldehydes and ketones. It can be carried out without a solvent and often gives nearly quantitative yields of the products. This straightforward and cost‐effective method is promising not only for laboratory application but also for industry, which produces carbon monoxide as a large‐scale waste product. [ABSTRACT FROM AUTHOR]

Rh‐catalyzed one‐step synthesis of tertiary and secondary amines from aldehydes and ketones, ammonium carbonate serving as nitrogen source, and carbon monoxide as a reducing agent has been developed. Aliphatic and aromatic aldehydes lead to the corresponding tertiary symmetrical amines in 69–83 % yields. Aromatic and aliphatic ketones lead to the corresponding secondary symmetrical amines which were obtained in 62–79 % yields. [ABSTRACT FROM AUTHOR]

A new protocol for the synthesis of nitriles from carbonyl compounds with elongation of the molecule with two carbon atoms was developed. It involves a reaction of ethyl cyanoacetate with different aldehydes in the presence of iron pentacarbonyl as a reducing agent. This protocol is very simple and requires only commonly available reagents, with no catalyst or complicated ligands being employed. A new protocol for the synthesis of nitriles from carbonyl compounds with elongation of the molecule with two carbon atoms was developed. It involves a reaction of ethyl cyanoacetate with different aldehydes in the presence of iron pentacarbonyl as a reducing agent. This protocol is very simple and requires only commonly available reagents, with no catalyst or complicated ligands being employed. [ABSTRACT FROM AUTHOR]

Abstract: The rapid development of enantioselective C−H activation reactions has created a demand for new types of catalysts. Herein, we report the synthesis of a novel planar‐chiral rhodium catalyst [(C5H2tBu2CH2tBu)RhI2]2 in two steps from commercially available [(cod)RhCl]2 and tert‐butylacetylene. Pure enantiomers of the catalyst were obtained through separation of its diastereomeric adducts with natural (S)‐proline. The catalyst promoted enantioselective reactions of aryl hydroxamic acids with strained alkenes to give dihydroisoquinolones in high yields (up to 97 %) and with good stereoselectivity (up to 95 % ee). [ABSTRACT FROM AUTHOR]

The reactions of thallium salt Tl[7-SMe2-7,8-C2B9H10] with [(cod)RhCl]2 and [Cp*RuCl]4 are accompanied by room-temperature polyhedral rearrangement, giving rhoda- and ruthenacarboranes 1-cod-8-SMe2-1,2,8-RhC2B9H10 ( 2) and 1-Cp*-8-SMe2-1,2,8-RuC2B9H10 ( 3), respectively. According to DFT calculations, the rearrangement could be attributed to the triangular face rotation mechanism. The reaction of iridium derivative 1-cod-8-SMe2-1,2,8-IrC2B9H10 ( 1) with anhydrous hydrohalic acids HX (X = Cl, Br, I) results in the dimeric halide iridacarboranes [1,1-X2-8-SMe2-1,2,8-IrC2B9H10]2 [ 4a- c; X = Cl ( a), Br ( b), I ( c)]. Bromide 4b reacts with Tl[Tl(η-7,8-C2B9H11)] and TlCp giving iridacarboranes 8′-SMe2-1,1′-Ir(2,3-C2B9H11)(2′,8′-C2B9H10) ( 5) and 1-Cp-8-SMe-1,2,8-IrC2B9H10 ( 6). The formation of the latter compound is accompanied by demethylation of the SMe2 substituent. The structures of 2, 3, 5 and 6 were determined by single-crystal X-ray diffraction. Iridacarboranes 4b and [1,1-Br2-4-SMe2-1,2,3-IrC2B9H10]2 ( 7) catalyze the dimerization of diphenylacetylene, giving 1,2,3-triphenylnaphthalene in 20-24 % yields. Compounds 4b and 7 also effectively catalyze the reductive amination reaction between aldehydes (or ketones) and primary (or secondary) amines in the presence of carbon monoxide, giving the corresponding secondary and tertiary amines in high yields (60-85 %). [ABSTRACT FROM AUTHOR]

An efficient method for the rhodium on carbon matrix catalyzed preparation of secondary and tertiary amines, cyanoesters, and nitriles through the reductive amination/alkylation of carbonyl compounds was developed, including a convenient procedure for the tandem formal reductive addition of acetonitrile to aldehydes. The catalyst could be reused, and at least three consecutive reaction cycles were performed with comparable efficiency. The method was shown to be compatible with functional groups prone to reduction by hydrogen and complex hydrides. [ABSTRACT FROM AUTHOR]

Die reduktive Aminierung ohne Wasserstoffquelle wurde entwickelt. Kohlenmonoxid wirkt hierbei als Reduktionsmittel. Die Reaktion läuft mit einer Vielzahl von Carbonylverbindungen und Aminen mit niedrigen Katalysatorladungen effektiv ab und ist mechanistisch interessant, da kein molekularer Wasserstoff beteiligt ist. [ABSTRACT FROM AUTHOR]

The aldol‐type reaction became one of the forefathers of C−C bond formation reactions. Advancements in the synthetic methodology resulted in the development of chemo‐, regio‐, and stereoselective processes. This Review focuses on reductive aldol‐type alkylation methods implemented to the synthesis of ten approved drug substances. Furthermore, retrosynthetic analysis demonstrates that other active pharmaceutical ingredients could be obtained via reductive Aldol‐type reactions. For more information, see the Review by S. Runikhina et al. on page 15327 ff. [ABSTRACT FROM AUTHOR]

A method of reductive amination without an external hydrogen source is reported. Carbon monoxide is used as the reductant. The reaction proceeds efficiently for a variety of carbonyl compounds and amines at low catalyst loadings and is mechanistically interesting as it does not seem to involve molecular hydrogen. [ABSTRACT FROM AUTHOR]

The Cover Feature shows juggling of aldehydes and cyanoacetate as balls in reducing hands to give nitriles with elongation of carbon chain with two atoms. A chemist juggles with different molecules to obtain new functionality after collisions of the "balls". Iron pentacarbonyl hand illustrates a tool that turns the result of this reaction to the desired pathway. In experienced hands, molecules undergo transformation. More information can be found in the Communication by D. Chusov et al. [ABSTRACT FROM AUTHOR]

Titanium(IV) catalysts generated in situ from Ti(OiPr)4 and BINOL-based bis salen-compounds are developed and successfully used as recyclable catalysts for the asymmetric ring-opening reaction of epoxides with TmsCN. [ABSTRACT FROM AUTHOR]