BINAP versus BINAP(O) in Asymmetric Intermolecular Mizoroki-Heck Reactions: Substantial Effects on Selectivities
作者:Thorsten H. Wöste、Martin Oestreich
DOI:10.1002/chem.201101695
日期:2011.10.10
2′‐Bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) was employed as chiral ligand in the enantioselective intermolecular Mizoroki–Heck reaction, whereas the use of cognate BINAP(O) (monooxidized BINAP) is unprecedented. The regio‐ and enantioselectivity of the arylation of representative cyclic alkenes changes dramatically in the presence of hemilabile BINAP(O) instead of BINAP. The arylation of 2,3‐dihydrofuran
2,2'-双(二苯基膦基)-1,1'-联萘(BINAP)在对映选择性分子间Mizoroki-Heck反应中用作手性配体,而同源BINAP(O)(单氧化BINAP)的使用是空前的。在存在半不稳定的BINAP(O)而不是BINAP的情况下,代表性环状烯烃芳基化的区域和对映选择性发生了巨大变化。2,3-二氢呋喃的芳基化具有极好的区域分散性(98:2对0:100),而环戊烯的芳基化仅与BINAP(O)对映选择性[60对映体过量10%对映体(ee)]。使用的[钯2(DBA)3 ] ⋅ DBA(DBA =苄基丙酮)代替钯(OAC)2产生高达86% ee值 在环戊烯的芳基化反应中