Asymmetric allylic alkylation with palladium coordinated to a new optically active pyrazolylmethane ligand
作者:M. Bovens、A. Togni、L.M. Venanzi
DOI:10.1016/0022-328x(93)83042-t
日期:1993.6
for the preparation of the ligands bis(4R-methyl-7R-isopropyl-4,5,6,7-tetrahydro-N2-indazolyl)methane, 5, bis(4R -methyl-7R-isopropyl-4,5,6,7-tetrahydro-N1,N2-indazolyl)methane, 6, and bis(4R-methyl-7R-isopropyl-4,5,6,7- tetrahydro-N1-indazolyl)methane, 7. Their complexes [Pd(η3-C3H5)(LL)][PF6] (LL = 5, 6 and 7); 9, 10, and 11, respectively, were used as catalyst precursors for the reaction of rac-(E)-1
由(-)-薄荷酮1制备旋光的吡唑4 R-甲基-7 R-异丙基-4,5,6,7-四氢吲唑3,并用于制备配体bis(4 R -甲基-7 R-异丙基-4,5,6,7-四氢-N 2-吲唑基)甲烷,5,双(4 R-甲基-7 R-异丙基-4,5,6,7-四氢-N 1,N 2-吲唑基)甲烷,6和双(4 R-甲基-7 R-异丙基-4,5,6,7-四氢-N 1-吲唑基)甲烷,7。它们的复合物[将Pd(η 3 -C 3 H ^ 5)(LL)] [PF 6 ](LL = 5,6和7); 9,10,和11,分别用作反应催化剂前体的外消旋- (ê)-1,3-二苯基- 3-乙酰氧基-1-丙烯,12,用丙二酸二甲酯,13。当使用配体6时,2-羰基甲氧基-3,5-二苯基-4-烯酸甲酯15,得自84%ee;结果表明,要获得高ee值,必须在反应混合物中添加1当量的氯离子。