Binap-Gold(I) versus Binap-Silver Trifluoroacetate Complexes as Catalysts in 1,3-Dipolar Cycloadditions of Azomethine Ylides
作者:María Martín-Rodríguez、Carmen Nájera、José M. Sansano、Abel de Cózar、Fernando P. Cossío
DOI:10.1002/chem.201101606
日期:2011.12.9
The 1,3‐dipolar cycloaddition between azomethine ylides and alkenes is efficiently catalysed by [(Sa)‐Binap‐Au(tfa)}2] (Binap=2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl; tfa=trifluoroacetyl). Maleimides, 1,2‐bis(phenylsulfonyl)ethylene, chalcone and nitrostyrene were suitable dipolarophiles even when using sterically hindered 1,3‐dipole precursors. The results obtained in these transformations improve
[(S a)-Binap-Au(tfa)} 2 ](Binap = 2,2'-双(二苯基膦基)-1,1'-联萘基; tfa =三氟乙酰基)。马来酰亚胺,1,2-双(苯磺酰基)乙烯,查尔酮和硝基苯乙烯是适合的双极性亲和剂,即使使用空间受阻的1,3-偶极前体也是如此。在这些转化中获得的结果改进了在[Binap–Ag(tfa)]催化的相同反应中获得的相似结果。此外,还进行了计算研究,以证明手性金(I)配合物表现出的高对映选择性以及在该转化过程中观察到的非线性效应。