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A double synergistic cascade reaction is reported, combining transition metal and amine catalysis. The reaction between vinyl cyclopropanes and enals renders the final cyclopentane derivatives in excellent yields and stereoselectivities.

Aryl- and alkyl substituted enals react according to the regioselective title reaction to form a mixture of three diastereomeric cyclopropanation products in high yields and with often very high enantioselectivities.

We describe the use of visible light in conjunction with an organic dye for the synthesis of phosphoramidates. Cross dehydrogenative coupling reactions between phosphites and amines are reported using organic dyes and light as catalysts for the first time. It is not only a novel application of organic dyes but also fulfils the requirement of sustainability and green chemistry avoiding the use of chromatographic purification techniques. The product was simply isolated from the reaction mixture via an acid-base work-up procedure, rendering the pure product in good yields.

Recently green chemistry has attracted much attention from organic chemists due the problems that our society faces in terms of waste generation and energy consumption. For this reason cross dehydrogenative couplings (CDC) have emerged as one of the most important strategies for C?C bond formation nowadays. In our research group, enticed by the use of organocatalytic cross dehydrogenative coupling reactions and in the synthesis of fluorinated compounds, we developed a new organocatalytic methodology based on the CDC activation of tetrahydroisoquinolines followed by addition of fluoromalonates. The reaction is simply catalyzed by organic dyes (Rose Bengal) using green LED as a light source and oxygen as stoichiometric oxidant and let us to obtain the final fluorinated compounds in good yields.

In the present paper we report our latest efforts in pushing the boundaries of synergistic catalysis. We propose the use of 3 different catalytic cycles working in concert for the formation of cis cyclopropane derivatives of benzoxazoles with excellent stereoselectivities. This is the proof of concept that synergistic catalysis could be successfully used in cascade reactions.

In this review the principal enantioselective methodologies merging transition-metal catalysis and aminocatalysis are disclosed. 1 Introduction 2 Transition-Metal and Enamine Catalysis 3 Transition-Metal and Iminium Catalysis 4 Transition-Metal Catalysis and Organocascade (Iminium/Enamine) Activation 5 Conclusions and Perspectives

Stereocontrolled formation of carbon-carbon and carbon-heteroatom bonds through asymmetric organocatalysis is a formidable challenge for modern synthetic chemistry. Among the most significant contributions to this field are the transformations involving the use of acetaldehyde or α-heteroatom-substituted acetaldehydes for constructing valuable synthons (e.g., amino acid derivatives and hydroxycarbonyl). In this Minireview, versatile (enantioselective) organocatalytic transformations are discussed.

We report herein a novel photocyclopropanation of dibromomalonates with alkenes in the presence of Hunig base. This protocol provides an environmentally benign approach for the synthesis of multisubstituted cyclopropanes, since no catalyst is required. The Photo-induced Electron Transfer (PET) from Hunig base to dibromomalonate is the key process during this transformation.

The reaction proceeds with low diastereoselectivity and all products are isolated as mixtures of diastereomers.

Treatment of the starting nitrile with equimolar amounts of Tf2O or TfOH produces a nitrilium salt which reacts with 2 equiv.

This paper describes the synthesis of a series of alkanethiols containing perfluorinated terminal segments: F(CF 2 ) m (CH 2 ) n SH, where m = 1, n = 9–15; m = 2, n = 11–14; m = 3, n = 10–13; and m = 4, n = 9–12. Fluorinated alkyl iodides of the general formula F(CF 2 ) m (CH 2 ) n I, where m = 1–4 and n = 0 or 1, were added to long-chain ω-olefins that were functionalized at the α-terminus with a thioacetate group. The reactions proceeded in good yields under free radical conditions. Reduction of the resulting secondary iodides gave long-chain alkanethioacetates with perfluoroalkyl terminal segments. These intermediates were readily transformed into the corresponding terminally perfluorinated alkanethiols by acidic deprotection. The product thiols should find use in the generation of well-defined fluorinated interfaces using the self-assembled monolayer (SAM) technique.

A new reaction based on synergistic catalysis, in which two catalytic cycles involving organometallic activation of an alkyl azaarene by AgOAc and Lewis base (DABCO) activation of a Morita—Baylis—Hillman carbonates, is developed.

The i-motif structure is formed in cytosine-rich sequences, its building block being the cytosine·cytosine + base pair. This structure is particularly stable at pH values below physiological (∼7.4) and, because of that, it has not attracted as much biological interest as other non-canonical structures such as the G-quadruplex. Nowadays, the proposal of potential roles in vivo, as well as nanotechnological applications, has produced an increasing interest in its study. In this context, the present work provides an overall picture of the i-motif structure. Those aspects related to formation and stability, such as chemical modifications or the interaction with ligands, are discussed. Special attention has been made to the i-motif structures that could have a hypothetical role in vivo, such as those present near the promoter region of several oncogenes.

Review: [recent progresses in the use of DNA nanoconstructs for molecular and cellular biology; 150 refs.

Highly enantioselective cascade reactions for the synthesis of fluoroindanes and chromanols derivatives are described. The cascade reactions consisted of either a double Michael reaction or Michael–hemiacetal formation via the addition of fluorobis(phenylsulfonyl)methane (FBSM) to enals. The final products were obtained in good yields with excellent stereoselectivities.

All synthesized compounds are screened for their in vitro activity against Plasmodium falciparum (W2) and cytotoxicity to Hep G2A16 cells.

An organocatalytic enantioselective synthesis of α-methylene-γ-lactams has been developed. The reaction between protected 2-aminomalonates and Morita–Baylis–Hillman carbonates is catalyzed by chiral Lewis bases to afford the corresponding lactams in excellent yields and moderate to good enantioselectivities, after work-up.

A new three-component cascade reaction for the synthesis of thiohydantoins is reported. The reaction between ?-amino esters, nitrostyrenes, and aromatic isothiocyanates is efficiently promoted by organic bases to afford highly substituted thiohydantoins in moderate to good yields and diastereoselectivities.

Nucleophilic addition to carbon–nitrogen double bonds (imines) represents one of the most common strategies for the synthesis of amine derivatives. In order to circumvent the problem associated with low reactivity of imines in nucleophilic addition, various imines with electron-withdrawing groups at nitrogen have been studied, and many of them were successfully applied in asymmetric methodologies. Especially N-carbamoyl imines were found to be useful in the enantioselective synthesis of various organic compounds, due to their increased reactivity toward nucleophiles as well as limited difficulties connected with the removal of the carbamoyl moiety in target molecules. The aim of this review is to cover enantioselective methods based on N-carbamoyl imines, focusing on synthetically useful protocols.

The diastereoselective 1,3-dipolar cycloadditions of achiral nitrones (I) with chiral acrylamide (II) is compared with the corresponding cycloadditions of chiral nitrones (V) with methyl acrylate.

Asymmetric γ-hydroxy nitriles are valuable intermediates because hydrolysis of the nitriles can result in an intramolecular cyclization to chiral γ-lactones, which have a variety of biological uses. Starting with an assortment of different aldehydes (alkyl and aryl) a 4-step synthesis of γ-keto nitriles was developed. These prochiral substrates were then screened against a library of ketoreductases for their ability to stereoselectively reduce the carbonyl. Enzymes from the short chain dehydrogenase family showed activity and these enzymatic reactions were scaled up to produce a diverse set of chiral γ-lactones.

The reaction between protected 2-hydroxymalonates (II) and Morita—Baylis—Hillman carbonates (I) is catalyzed by chiral cinchona-derived Lewis bases.

Starting from carbamate (I), the title reaction sequence affords pentasubstituted tetrahydropyrans with high diastereo- and enantioselectivity.

Oligonucleotide-peptide conjugates have attracted considerable interest especially for biomedical uses. In the first part of this chapter, we describe protocols for the stepwise synthesis of oligonucleotides carrying peptide sequences at the 3'-end on a single support. The resulting oligonucleotide-peptide conjugates may be used as exogenous effectors for the specific control of gene expression. In the second part of this chapter, detailed postsynthetic conjugation protocols to introduce peptide sequences into oligonucleotide sequences are also presented.

Surface-enhanced Raman scattering (SERS) is one of the most straightforward applications of the so-called nanoplasmonics. This powerful molecular spectroscopy technique is based on the enhancement of the inelastic scattering from molecules located near nanostructured metallic surfaces when these are illuminated and surface plasmons are excited. The analytical applications of SERS are hindered when the Raman cross-section of the analyte is too low, which is often the case in inorganic molecular species. This problem is even more serious when atomic species are to be identified, since these cannot display a vibrational signal. Herein we discuss the recent advancements toward the SERS detection of small inorganic compounds, including both molecular and atomic species.

A practical asymmetric allylic substitution of Baylis—Hillman carbonates (I) with 2-fluoromalonate (II) is achieved in the presence of β-isocupreidine as organocatalyst.