Total Synthesis of (-)-Corynantheidine by Nickel-Catalyzed Carboxylative Cyclization of Enynes
作者:Takashi Mizuno、Yoshihiro Oonishi、Masanori Takimoto、Yoshihiro Sato
DOI:10.1002/ejoc.201100147
日期:2011.5
The totalsynthesis of (―)-corynantheidine has been achieved through Ni°-mediated carboxylativecyclization as the key reaction step with incorporation of CO 2 , and this cyclization was also successfully expanded to the catalytic reaction by using Et 2 Zn in the presence of an excess amount of DBU.
Unexpected cis selectivity in the Pictet–Spengler reaction
作者:Patrick D. Bailey、Mark A. Beard、Theresa R. Phillips
DOI:10.1016/j.tetlet.2009.03.121
日期:2009.7
Whilst cis:trans selectivity of about 4:1 can be obtained from Pictet-Spengler reactions between tryptophan methyl esters and aldehydes using conditions of kinetic control, much higher cis selectivity (>95:5) can be obtained when both the tryptophan derivative and the aldehyde possess a Suitable pi-system: preliminary results oil the scope and limitations of this exceptional stereocontrol are presented in this Letter. (C) 2009 Elsevier Ltd. All rights reserved.