作者:Ashok K. Basak、Naoyuki Shimada、William F. Bow、David A. Vicic、Marcus A. Tius
DOI:10.1021/ja103028r
日期:2010.6.23
An organocatalytic asymmetric Nazarov cyclization of diketoesters that proceeds by means of a dual activation mechanism has been developed. Screening of a number of catalysts led to a new thiourea that incorporates a primary amino group. The method gives rise to cyclic products with two adjacent quaternaryasymmetriccarbon atoms, one of which is an all-carbon stereocenter, with complete or nearly
作者:Kei Kitamura、Naoyuki Shimada、Craig Stewart、Abdurrahman C. Atesin、Tülay A. Ateşin、Marcus A. Tius
DOI:10.1002/anie.201500881
日期:2015.5.18
A Pd0‐catalyzed asymmetric Nazarov‐type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL‐derived phosphoramidite (TADDOL=α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one