Concise synthesis of optically active ring-A substituted tryptophans
作者:Chunrong Ma、Xiaoxiang Liu、Shu Yu、Shuo Zhao、James M. Cook
DOI:10.1016/s0040-4039(98)02497-6
日期:1999.1
A concise synthesis of optically active trytophan derivatives was developed via diastereoselective alkylation of the Schöllkopfchiralauxiliary 4 to provide alkyne 2 which underwent palladium-catalyzedheteroannulation with iodoanilines 1 to furnish protected tryptophans 3. Hydrolysis and subsequent saponification of 3 provided the desired tryptophans 12 in good yields.
Efficient Asymmetric Synthesis of Biologically Important Tryptophan Analogues via a Palladium-Mediated Heteroannulation Reaction
作者:Chunrong Ma、Xiaoxiang Liu、Xiaoyan Li、Judith Flippen-Anderson、Shu Yu、James M. Cook
DOI:10.1021/jo001679s
日期:2001.6.1
A novel and concise synthesis of optically active tryptophan derivatives was developed via a palladium-catalyzed heteroannulation reaction of substituted o-iodoanilines with an internal alkyne. The required internal alkyne 14a or 25 was prepared in greater than 96% de via alkylation of the Schöllkopf chiral auxiliary 19 employing diphenyl phosphate as the leaving group. The Schöllkopf chiral auxiliary