“Matched/Mismatched” Diastereomeric Dirhodium(II) Carboxamidate Catalyst Pairs. Structure−Selectivity Correlations in Diazo Decomposition and Hetero-Diels−Alder Reactions
作者:Michael P. Doyle、John P. Morgan、James C. Fettinger、Peter Y. Zavalij、John T. Colyer、Daren J. Timmons、Michael D. Carducci
DOI:10.1021/jo050609o
日期:2005.6.1
been produced in good yields, and the X-ray crystal structure of each dirhodium(II) compound has been obtained. The incorporation of additional stereocenters into the dirhodium(II) ligands leads to recognizable levels of double asymmetric induction for C−H insertion, cyclopropanation, and hetero-Diels−Alder cycloaddition applications. The configurationally “matched” cases provide modest increases in enantioselectivity
均连接的氨基甲酸二吡啶鎓(II)提供了定义明确的结构框架,可用于研究催化剂控制的多重不对称诱导(“匹配/不匹配”效应)。非对映体对甲基-2-氧代咪唑烷-4(的小号)含有2-苯基环丙烷(4 -羧酸叔丁酯配体小号,2'小号,3'小号-HMCPIM和4小号,2' - [R,3' - [R -HMCPIM)和Ñ -benzenesulfonylproline (4 S, 2'小号-HBSPIM和4 S, 2' - [R -HBSPIM)在1-附件ñ酰基站点已经制备; 生成的(顺-2,2)-Rh已经以高收率生产了2 L 4化合物,并且已经获得了每种(II)化合物的X射线晶体结构。将附加的立体中心并入dirhodium(II)配位体可导致C-H插入,环丙烷化和杂Diels-Alder环加成应用中可识别的双不对称诱导水平。相对于模型催化剂Rh 2(MPPIM)4,构型“匹配”的情况对于分子内CH插入反应