Palladium catalysis in bridge-forming reactions between stereoselectively substituted glycine auxiliaries
作者:Bjørg S. Møller、Tore Benneche、Kjell Undheim
DOI:10.1016/0040-4020(96)00422-x
日期:1996.6
The disulfide bridge in cystine has formally been replaced by substitution of two α-alanines at the β-carbon into the 2,3-positions in 1,3-butadiene. The key reactions are stereoselective alkylation of lithiated (2S)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine with 2,3-dibromopropene. The alkene-alkene bond formation was effected by Pd-catalysis either with the 2′-bromoallyl products from the alkylation
胱氨酸中的二硫键已正式替换为在β-碳上的两个α-丙氨酸取代为1,3-丁二烯的2,3-位。关键反应是将锂化的(2 S)-2,5-二氢-3,6-二甲氧基-2-异丙基吡嗪与2,3-二溴丙烯进行立体选择性烷基化。烯烃-烯烃键的形成通过Pd催化,以烷基化反应的2'-溴烯丙基产物为底物或相应的氨基酸得到适当保护。