After an initial period of validating asymmetric organocatalysis by using a wide range of important model reactions that constitute the essential tools of organic synthesis, the time has now been reached when organocatalysis can be used to address specific issues and solve pending problems of stereochemical relevance. This Review deals with selected studies reported in 2006 and the first half of 2007, and is intended to highlight four main aspects that may be taken as testimony of the present status and prospective of organocatalysis: a) chemical efficiency; b) discovery of new substrate combinations to give new asymmetric syntheses; c) development of new catalysts for specific purposes by using mechanistic findings; and d) applications of organocatalytic reactions in the asymmetric total synthesis of target natural products and known compounds of biological and pharmaceutical relevance.

Asymmetric Organocatalysis: From Infancy to Adolescence

Asymmetric aldol reactions are a powerful method for the construction of carbon–carbon bonds in an enantioselective fashion. Historically this reaction has been performed in a stoichiometric fashion to control the various aspects of chemo-, diastereo-, regio- and enantioselectivity, however, a more atom economical approach would unite high selectivity with the use of only a catalytic amount of a chiral promoter. This critical review documents the development of direct catalytic asymmetric aldol methodologies, including organocatalytic and metal-based strategies. New methods have improved the reactivity, selectivity and substrate scope of the direct aldol reaction and enabled the synthesis of complex molecular targets (357 references).

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The Direct Catalytic Asymmetric Aldol Reaction

We are grateful to the Spanish Ministerio de Educacion y
Ciencia, as well as to Generalitat Valenciana and
University of Alicante, for their continuous financial
support.

Enantioselective direct aldol reaction: the blossoming of modern organocatalysis

Nach einer ersten Phase orientierender Studien zur asymmetrischen Organokatalyse, die vornehmlich der Untersuchung wichtiger Modellreaktionen der organischen Synthese galten, sind die Forschungen auf diesem Gebiet nun in einem Stadium angelangt, in dem speziellere Aufgabenstellungen und insbesondere auch stereochemische Probleme gezielt angegangen werden konnen. Dieser Aufsatz diskutiert ausgewahlte Arbeiten aus dem Jahr 2006 und der ersten Halfte von 2007 und soll vier Hauptaspekte hervorheben, an denen sich der gegenwartige Stand und die Perspektiven der Organokatalyse ablesen lassen: 1) chemische Effizienz; 2) Auffinden neuer Substratkombinationen fur die Entwicklung neuer asymmetrischer Synthesen; c) Entwicklung neuer Katalysatoren fur spezielle Anwendungen auf der Grundlage mechanistischer Erkenntnisse; d) Einsatz organokatalytischer Reaktionen in asymmetrischen Totalsynthesen von bisher unzuganglichen Naturstoffen und von bekannten biologisch und pharmazeutisch aktiven Verbindungen.

Asymmetrische Organokatalyse: Eintritt in die Reifezeit†

Asymmetric organocatalysis is now recognized as the third pillar of asymmetric synthesis. Recent years have witnessed increasing interest towards the use of highly active and stereoselective organocatalysts. This critical review documents the advances in the development of chiral organocatalysts which are systematically used in ≤3 mol% loading in all the sub-areas of the field, namely aminocatalysis, Bronsted acids and bases, Lewis acids and bases, hydrogen bond-mediated catalysis, phase transfer and N-heterocyclic carbene catalyses (194 references).

Low-loading asymmetric organocatalysis

Highly Enantioselective Organocatalytic Direct Aldol Reaction in an Aqueous Medium

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Vishnu Maya

Papers

Highly Enantioselective Organocatalytic Direct Aldol Reaction in an Aqueous Medium

Highly Enantioselective Organocatalytic Direct Aldol Reaction in an Aqueous Medium.

Yet Another Direct Aldol Reaction in Water