EFFECTIVE USES OF DIRHODIUM(II) TETRAKIS[METHYL 2-OXOPYRROLIDINE-5(R OR S)-CARBOXYLATE] FOR HIGHLY ENANTIOSELECTIVE INTERMOLECULAR CYCLOPROPENATION REACTIONS
EFFECTIVE USES OF DIRHODIUM(II) TETRAKIS[METHYL 2-OXOPYRROLIDINE-5(R OR S)-CARBOXYLATE] FOR HIGHLY ENANTIOSELECTIVE INTERMOLECULAR CYCLOPROPENATION REACTIONS
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DOI：
10.1021/ja00098a009
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发表时间：
1994-09-21
影响因子：
15
通讯作者：
SHAPIRO, EA
中科院分区：
文献类型：
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作者：
DOYLE, MP;PROTOPOPOVA, M;SHAPIRO, EA
标题化合物是L-炔烃与重氮酯和重氮酰胺分子间环丙烯反应的有效催化剂。与d-或L-薄荷基重氮乙酸酯的适当匹配所获得的非对映选择性为77到大于或等于94%DE。3-甲氧基-1-丙炔和3，3-二乙氧基-1-丙炔对映体选择性大于或等于94%ee。金属卡宾加成到炔烃的这些值的变化与炔烃或卡宾取代基的电子和/或空间影响有关。N，N-二甲基重氮乙酰胺比重氮酸酯提供更高水平的对映体控制。已确定了环丙烯产物的绝对构型：四[2-氧代吡咯烷-5(S)-羧酸甲酯]，Rh-2(5S-MEPY)(4)生成具有(S)-构型的2-取代-2-环丙烯-1-羧酸酯，而使用Rh-2(5R-MEPY)(4)则以(R)-构型提供这些环丙烯产物。这些环丙烯羧酸盐的二亚胺还原反应只产生顺式二取代的环丙烷产品。
The title compounds are effective catalysts for intermolecular cyclopropenation reactions of l-alkynes with diazo esters and diazo amides. Diastereoselectivities achieved from the appropriate match with d- or l-menthyl diazoacetate are 77 to greater than or equal to 94% de. Enantioselectivities up to greater than or equal to 94% ee with 3-methoxy-1-propyne and 3,3-diethoxy-1 -propyne have been obtained. Variations in these values for metal carbene additions to alkynes are associated with electronic and/or steric influences from the alkyne or carbene substituents. N,N-Dimethyldiazoacetamide provides a higher level of enantiocontrol than do diazo esters. The absolute configurations of the cyclopropene products have been established; dirhodium(II) tetrakis[methyl 2-oxopyrrolidine-5(S)-carboxylate], Rh-2(5S-MEPY)(4), produces 2-substituted-2-cyclopropene-1-carboxylates having the (S)-configuration whereas use of Rh-2(5R-MEPY)(4) provides these cyclopropene products in the (R)-configuration. Diimide reduction of these cyclopropenecarboxylates produces the cis-disubstituted cyclopropane products exclusively.