Copper-Catalyzed Synthesis of Axially Chiral Biaryls with Diaryliodonium Salts as Arylation Reagents

NOBIN and BINAM derivatives harboring biaryl frameworks are recognized as a class of important atropisomers with versatile applications. Here, we present an efficient synthetic route to access such compounds through copper-catalyzed domino arylation of N-arylhydroxylamines or N-arylhydrazines with diaryliodonium salts and [3,3]-sigmatropic rearrangement. This reaction features mild conditions, good substrate compatibility, and excellent efficiency. The practicality of this protocol was further extended by the synthesis of biaryl amino alcohols.     

Highly stereoselective direct aldol reactions catalyzed by (S)-NOBIN-l-prolinamide

(S)-NOBIN-l-prolinamide was employed as organocatalyst in the direct aldol reactions of different ketones and aromatic aldehydes using dioxane as solvent and in the presence of water as additive. Acetone led to the aldol products in up to 93% ee, while cyclic ketones furnished the anti-aldols in moderate to high yield, excellent diastereoselectivity (up to >99/<1 anti/syn ratio) and high ee (up to 95%).     

新型P,N配体及基1,4-共轭加成反应

以2-萘酚为起始原料,经过氧化偶联,消旋体的拆分得到手性骨架2-氨基-2'-羟基-1,1'-联萘(NOBIN),并以S-NOBIN为原料,经过六步反应合成了两个新型配体S-(+)-2-(2-吡啶酰胺基)-2'-二苯基膦基-1,1'-联萘(1a)和S-(+)-2-(6-甲基-2-吡啶酰胺基)-2'-二苯基膦基-1,1'-联萘(1b)。并进行了铜配合物催化的二乙基锌对2-环己烯酮的1,4-共轭加成反应的研究。反应产物3-乙基环己酮(13)的e.e.值高达92%。     

Rationally designed organocatalyst for direct asymmetric aldol reaction in the presence of water

A rationally designed organocatalyst for direct asymmetric aldol reaction in the presence of water has been developed. High yield (up to 99%), diastereoselectivity (up to 99:1) and enantioselectivity (up to 97%) were obtained under optimal conditions.