Catalytic enantioselective allylation at the activated benzylic position of prochiral aryl cyano esters: access to quaternary stereogenic centers
摘要:
Palladium catalyzed asymmetric allylic alkylation of prochiral aryl cyano esters has been carried out in the presence of various chiral ligands. The base and additives have been varied and allowed to produce the allyl derivative presenting a highly functionalized quaternary stereogenic center. The chiral pocket ligands of Trost appears the most appropriate to produce the desired chiral derivative. (C) 2005 Elsevier Ltd. All rights reserved.
Catalytic enantioselective allylation at the activated benzylic position of prochiral aryl cyano esters: access to quaternary stereogenic centers
摘要:
Palladium catalyzed asymmetric allylic alkylation of prochiral aryl cyano esters has been carried out in the presence of various chiral ligands. The base and additives have been varied and allowed to produce the allyl derivative presenting a highly functionalized quaternary stereogenic center. The chiral pocket ligands of Trost appears the most appropriate to produce the desired chiral derivative. (C) 2005 Elsevier Ltd. All rights reserved.
Acetone Cyanohydrin as a Source of HCN in the Cu-Catalyzed Hydrocyanation of α-Aryl Diazoacetates
作者:Eun Ju Park、Seungeon Lee、Sukbok Chang
DOI:10.1021/jo100356d
日期:2010.4.16
A procedure for the Cu-catalyzed hydrocyanation of α-aryl diazoesters has been developed using acetone cyanohydrin as a source of hydrogencyanide (HCN). It was found that the addition of trimethylsilyl cyanide (TMSCN) significantly accelerates the conversion presumably by delivering free cyanide ion in situ, thus producing various types of α-aryl cyanoacetates in high yields under mild conditions
Highly Selective Preparation of a Chiral Quaternary Allyl Aryl Piperidinedione by Palladium-Catalyzed Asymmetric Allylation Under Solid-Liquid Phase-Transfer Catalysis
The asymmetric allylic alkylation of prochiral aryl cyano esters has been carried out in the presence of a bi-component catalytic system containing a palladium and a rhodium complex modified by phosphorus containing chiral auxiliaries. The allyl derivatives were isolated in up to 63% ee. The chiral pocket ligands of Trost appear the most appropriate to produce the desired chiral derivatives. (c) 2005 Elsevier Ltd. All rights reserved.
Catalytic enantioselective allylation at the activated benzylic position of prochiral aryl cyano esters: access to quaternary stereogenic centers
Palladium catalyzed asymmetric allylic alkylation of prochiral aryl cyano esters has been carried out in the presence of various chiral ligands. The base and additives have been varied and allowed to produce the allyl derivative presenting a highly functionalized quaternary stereogenic center. The chiral pocket ligands of Trost appears the most appropriate to produce the desired chiral derivative. (C) 2005 Elsevier Ltd. All rights reserved.