Recent Advances In Asymmetric Synthesis Research Articles

Recent Advances in Asymmetric Synthesis of Chiral Cyclobutenes

AbstractCyclobutene scaffolds occur in natural products and bioactive compounds. Their unique structural features and intrinsic ring strain make cyclobutene a type of important building block in synthetic chemistry. In recent years, considerable efforts have been dedicated to the synthesis of chiral cyclobutenes. Enantioselective [2+2] cycloadditions and functionalization of cyclobutene derivatives have emerged as powerful and reliable protocols for achieving this goal, resulting in significant progress in this field. This review provides a comprehensive summary of the recent advancements in the asymmetric synthesis of chiral cyclobutenes, and the discussion is logically divided into four parts according to the reaction mode.

Recent advances in asymmetric synthesis of chiral amides and peptides: racemization-free coupling reagents.

Over past decades, chiral amides and peptides have emerged as powerful and versatile compounds due to their various biological activities and interesting molecular architectures. Although some chiral condensation reagents have been applied successfully for their synthesis, the introduction of racemization-free methods of amino acid activation have shown lots of advantages in terms of their low cost and low toxicity. In this review, advancements in amide and peptide synthesis using racemization-free coupling reagents over the last 10 years are summarized. Various racemization-free coupling reagents have been applied in the synthesis of enantioselective amides and peptides, including ynamides, allenones, HSi[OCH(CF3)2]3, Ta(OMe)5, Nb(OEt)5, Ta(OEt)5, TCFH-NMI, water-removable ynamides, DBAA, DATB, o-NosylOXY, TCBOXY, Boc-Oxyma, NDTP, 9-silafluorenyl dichlorides, the Mukaiyama reagent, EDC and T3P. The racemization-free reagents described in this review provide an alternative greener option for the asymmetric synthesis of chiral amides and peptides. We hope that this review will inspire further studies and developments in this field.

Recent advances in asymmetric synthesis of chiral benzoheterocycles via Earth-abundant metal catalysis

This review mainly focus on the assembly of chiral benzoheterocycles, such as dihydrobenzofurans, chromans, indolines, tetrahydroquinolines, etc., via Earth-abundant metal-catalyzed (Cu, Fe, Ni, and Ti) asymmetric synthesis in the last few decades.

Recent Advances in Asymmetric Synthesis of Pyrrolidine-Based Organocatalysts and Their Application: A 15-Year Update

In 1971, chemists from Hoffmann-La Roche and Schering AG independently discovered a new asymmetric intramolecular aldol reaction catalyzed by the natural amino acid proline, a transformation now known as the Hajos-Parrish-Eder-Sauer-Wiechert reaction. These remarkable results remained forgotten until List and Barbas reported in 2000 that L-proline was also able to catalyze intermolecular aldol reactions with non-negligible enantioselectivities. In the same year, MacMillan reported on asymmetric Diels-Alder cycloadditions which were efficiently catalyzed by imidazolidinones deriving from natural amino acids. These two seminal reports marked the birth of modern asymmetric organocatalysis. A further important breakthrough in this field happened in 2005, when Jørgensen and Hayashi independently proposed the use of diarylprolinol silyl ethers for the asymmetric functionalization of aldehydes. During the last 20 years, asymmetric organocatalysis has emerged as a very powerful tool for the facile construction of complex molecular architectures. Along the way, a deeper knowledge of organocatalytic reaction mechanisms has been acquired, allowing for the fine-tuning of the structures of privileged catalysts or proposing completely new molecular entities that are able to efficiently catalyze these transformations. This review highlights the most recent advances in the asymmetric synthesis of organocatalysts deriving from or related to proline, starting from 2008.

Recent Advances in Asymmetric Synthesis of P-Chiral Phosphine Oxides

Recent Advances in Asymmetric Synthesis of P-Chiral Phosphine Oxides

Catalytic asymmetric synthesis of α-stereogenic carboxylic acids: recent advances.

Chiral carboxylic acids bearing an α-stereogenic center constitute the backbone of many natural products and therapeutic reagents as well as privileged chiral ligands and catalysts. Hence, it is not surprising that a large number of elegant catalytic asymmetric strategies have been developed toward the efficient synthesis of α-chiral carboxylic acids, such as α-hydroxy acids and α-amino acids. In this review, the recent advances in asymmetric synthesis of α-stereogenic free carboxylic acids via organocatalysis and transition metal catalysis are summarized (mainly from 2010 to 2020). The content is organized by the reaction type of the carboxyl source involved, including asymmetric functionalization of substituted carboxylic acids, cyclic anhydrides, α-keto acids, substituted α,β-unsaturated acids and so on. We hope that this review will motivate further interest in catalytic asymmetric synthesis of chiral α-substituted carboxylic acids.

Recent advances in asymmetric synthesis with CO2

Carbon dioxide (CO2) is an important and appealing C1 building block in chemical synthesis due to its nontoxicity, abundance, availability and sustainability. Tremendous progress has been achieved in the chemical transformation of CO2 into high value-added organic chemicals. However, the asymmetric synthesis with CO2 to form enantioenriched molecules, especially the catalytic process, has lagged far behind. The enantioselective incorporation of CO2 into organic compounds is highly desirable, as the corresponding chiral products, such as carboxylic acids and amino acids, are common structural units in a vast array of natural products and biologically active compounds. Herein, we discuss recent progress toward the enantioselective incorporation of CO2 into organic molecules, which mainly rely on three strategies: 1) kinetic resolution or desymmetrization of epoxides with CO2 to form chiral cyclic carbonates and polycarbonates; 2) nucleophilic attack of O- or N-nucleophiles to CO2 in tandem with asymmetric C–O bond formation to prepare chiral cyclic carbonates and carbamates; 3) direct enantioselective nucleophilic attack of organometallic reagents to CO2 with asymmetric C–C bond formation. Finally, challenges and future outlook in this area are also presented.

Recent advances in asymmetric synthesis of 2-substituted indoline derivatives

ABSTRACT Enantiomerically pure 2-substituted indolines are an important class of nitrogen heterocycles that occur frequently in many alkaloid natural products and biologically active compounds. Consequently, the synthesis of such skeletons is of great significance. The past years have witnessed a number of remarkable advances in the development of efficient strategies to construct this class of chiral compounds. This review summarizes the recent advances in asymmetric synthesis of 2-substituted indoline derivatives. Due to the limitation of the length, this review only summarizes those works published from January of 2012 to January of 2019. Meanwhile, methods towards synthesis of fused and spirocyclic indolines will not be discussed in this review.

Recent progress in asymmetric synthesis of aziridine derivatives (microreview)

This microreview describes recent advances in asymmetric synthesis of aziridine derivatives, which have been published over the last two years.

ChemInform Abstract: Recent Advances in Asymmetric Synthesis of P — Stereogenic Phosphorus Compounds

AbstractReview: [201 refs.

Recent Advances in Asymmetric Synthesis of Optically Active Indole Derivatives from 3-Indolylmethanols

吲哚-3-基甲醇在酸作用下原位生成亲电性的类乙烯基亚胺（离子）中间体,然后在手性催化剂催化下被亲核试剂进攻生成具有潜在生物活性的光学活性3-取代吲哚衍生物.综述了吲哚-3-基甲醇不对称烷基化反应、不对称还原反应以及不对称重排反应合成光学活性3-取代吲哚衍生物的研究进展.

Recent Advances in Asymmetric Synthesis of Oxacephems

Recent Advances in Asymmetric Synthesis of Oxacephems

ChemInform Abstract: Recent Advances in Enzymatic and Chemical Deracemisation of Racemic Compounds

AbstractReview: 41 refs.

Recent advances in asymmetric synthesis of Р-stereogenic phosphorus compounds.

This chapter points out significant advances in the asymmetric synthesis of P-chiral organophosphorus compounds with many applications in stereoselective synthesis and in asymmetric catalysis, making reference to updated literature findings as well as the author's original research. Asymmetric addition and cycloaddition reactions, oxidation, including metal catalyzed and non-metal biocatalytic methods are described, in addition to synthetic approaches via nucleophilic substitution of appropriately substituted precursors. Use of chiral organophosphorus compounds in some asymmetric transformations such as hydrogenation and alkyl/arylation reactions is also discussed.

Recent advances in enzymatic and chemical deracemisation of racemic compounds

Deracemisation of racemic compounds is still the most important strategy to produce optically pure compounds despite many recent advances in asymmetric synthesis. Especially deracemisation approaches that give rise to single enantiomers are preferred, which can be achieved either by invoking organocatalysts, metal complexes or enzymes - leading to dynamic kinetic resolution - or by applying other deracemisation techniques based on stereoinversion or enantioconvergence. In this tutorial review, we will provide an overview of new, recently developed approaches that lead to the important goal of creating organic compounds of single chirality.

Recent advances in the semi-pinacol rearrangement of α-hydroxy epoxides and related compounds

The semi-pinacol rearrangement is fast becoming an extremely reliable reaction in organic synthesis allowing the rapid construction of relatively complex stereodefined products in high yield. Recent advances in asymmetric synthesis have also enabled enantiopure precursors to partake in the rearrangement showing that extremely high levels of stereospecificity are observed. In this critical review recent advances in the semi-pinacol rearrangement over the past 15 years are examined which demonstrate the extremely high utility of this reaction towards the development of structurally diverse organic building blocks (74 references).

Recent Advances in Asymmetric Synthesis of Pipecolic Acid and Derivatives

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Use of chiral sulfoxides in asymmetric synthesis

This report is intended to update the most recent advances in asymmetric synthesis using chiral sulfoxides, focusing on their use as chiral auxiliaries from 2000 to 2006 and their applications in the synthesis of biologically active products. The main purpose of this review is to demonstrate the growing potential of these chiral sulfur reagents in transmitting chirality to other centres, establishing the sulfinyl group as one of the most stereocontrolling elements in numerous asymmetric reactions. <div class= textboxdefault > Figure options Download full-size image Download as PowerPoint slide

Recent advances in asymmetric synthesis of pipecolic acid and derivatives

This review covers the literature relating to asymmetric syntheses of pipecolic acid derivatives from 1997 to present. This review is organized according to the position and the degree of substitution of the piperidinic cycle. In a first section, syntheses of pipecolic acid itself are described. Then, successively, syntheses of C-3, C-4, C-5, C-6 substituted pipecolic acid derivatives are reported. Finally, syntheses of unsaturated pipecolic acid derivatives are presented before the last part devoted to the polysubstituted pipecolic acid derivatives.

Recent Advances in Asymmetric Synthesis with Chiral Imide Auxiliaries

AbstractFor Abstract see ChemInform Abstract in Full Text.