The current state-of-the-art synthesis for the formation of enantiomerically enriched all-carbon quaternary stereocenters in acyclic system relies on the formation of a single carbon-carbon bond per chemical step by asymmetric catalysis. These extraordinary sophisticated methods were logically classified among the most powerful and innovative ones. In this concept article, we are proposing a new retrosynthetic
New Multicomponent Approach for the Creation of Chiral Quaternary Centers in the Carbonyl Allylation Reactions
作者:Genia Sklute、Ilan Marek
DOI:10.1021/ja060498q
日期:2006.4.1
combined regio- and stereo-controlled carbometalation reaction of alkynyl sulfoxide followed by a zinc homologation and finally an allylation reaction led, in a single-pot operation, to chiral homoallylic alcohols in excellent yields and diastereoselectivities for the creation of chiral quaternary and tertiary centers. The key features in all of the reactions that are described in this article are the high
Highly Stereoselective Synthesis of Functionalized β,β-Di- and Trisubstituted Vinylic Sulfoxides by Cu-Catalyzed Conjugate Addition of Organozinc Reagents
β,β-Disubstituted chiral vinylic sulfoxides bearing functionalities have been synthesized via Cu-catalyzed conjugateaddition of organozincreagents to chiral 1-alkynyl sulfoxides. Due to the availability of functionalized organozincreagents and high syn-selectivity of the reaction, both geometric β,β-disubstituted vinylic sulfoxides were selectively synthesized. Furthermore, 1-alkynyl sulfoxides
Geometrically Selective Synthesis of Functionalized β,β-Disubstituted Vinylic Sulfoxides by Cu-Catalyzed Conjugate Addition of Organozinc Reagents to 1-Alkynyl Sulfoxides
functionalities has been developed by employing Cu-catalyzed conjugateaddition of an organozincreagent to chiral 1-alkynyl sulfoxide. Since the reaction proceeds with very high syn-selectivity, both geometric beta,beta-disubstituted vinylic sulfoxides were stereoselectively synthesized by changing the combination of 1-alkynyl sulfoxide and the organozincreagent.
Sulfur-Directed Enantioselective Synthesis of Functionalized Dihydropyrans
作者:Roberto Fernández de la Pradilla、Mariola Tortosa、Nadia Lwoff、Miguel A. del Águila、Alma Viso
DOI:10.1021/jo801029q
日期:2008.9.1
dihydropyrans. The scope of this methodology, including the preparation of seven-membered rings, has been studied in depth. The reactivity of our sulfinyl dihydropyrans toward oxidation, imination, and dihydroxylation has been explored, and thus several routes to densely functionalized pyran derivatives have been outlined. The reactivity of allylic dihydropyranyl sulfones and sulfoximines in S(N)2'