On July 29, 2015, Kalek, Marcin; Fu, Gregory C. published an article.Category: chlorides-buliding-blocks The title of the article was Phosphine-Catalyzed Doubly Stereoconvergent γ-Additions of Racemic Heterocycles to Racemic Allenoates: The Catalytic Enantioselective Synthesis of Protected α,α-Disubstituted α-Amino Acid Derivatives. And the article contained the following:
Methods have recently been developed for the phosphine-catalyzed asym. γ-addition of nucleophiles to readily available allenoates and alkynoates to generate useful α,β-unsaturated carbonyl compounds that bear a stereogenic center in either the γ or the δ position (but not both) with high stereoselectivity. The utility of this approach would be enhanced considerably if the stereochem. at both termini of the new bond could be controlled effectively. In this report, we describe the achievement of this objective, specifically, that a chiral phosphepine can catalyze the stereoconvergent γ-addition of a racemic nucleophile to a racemic electrophile; through the choice of an appropriate heterocycle as the nucleophilic partner, this new method enables the synthesis of protected α,α-disubstituted α-amino acid derivatives in good yield, diastereoselectivity, and enantioselectivity. Thus, e.g., γ-addition of oxazolone (±)-I with (±)-allenoate II in presence of chiral phosphepine (S)-III yielded IV (91% ee, 14:1 dr). The experimental process involved the reaction of Methyl 6-chloro-6-oxohexanoate(cas: 35444-44-1).Category: chlorides-buliding-blocks
The Article related to phosphine catalyzed stereoconvergent addition racemic heterocycle allenoate, enantioselective synthesis protected amino acid derivative, Amino Acids, Peptides, and Proteins: Amino Acids and other aspects.Category: chlorides-buliding-blocks
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics