Use of new chiral tricoordinated phosphorus borane complexes in enantioselective borane reduction of ketones: Complexes structure and mechanistic studies
作者:Jean-Michel Brunel、Olivier Chiodi、Bruno Faure、Frédéric Fotiadu、Gérard Buono
DOI:10.1016/s0022-328x(96)06614-4
日期:1997.2
New tricoordinated phosphorus borane complexes were synthesized and their use as catalysts in enantioselective borane reduction of prochiral aromatic and aliphatic ketones was investigated. The structure of (2R,5S)-2-o-anisyl-3-oxa-1-aza phosphabicyclo[3.3.0]octane—borane complex 1b and (2R,5S)-2,3-diphenyl-1,3-diazaphosphabicyclo[3.3.0]octane—borane complex 6a was established by X-ray diffraction
合成了新的三配位硼硼烷配合物,并研究了其作为催化剂用于手性芳族和脂肪族酮的对映选择性硼烷还原的作用。(2 R,5 S)-2-邻-茴香基-3-氧杂-1-氮杂磷双环[3.3.0]辛烷-硼烷配合物1b和(2 R,5 S)-2,3-二苯基-的结构1,3-二氮杂磷双环[3.3.0]辛烷-硼烷络合物6a通过X射线衍射分析确定。氧杂氮磷硼烷硼烷配合物的结构与在还原苯乙酮中所获得的对映选择性之间存在关系,二者均用2mol%和1当量的催化剂。在所测试的不同的氧杂氮杂膦硼烷配合物中,只有配合物1-3(包括3-氧杂-1-氮杂磷杂双环[3.3.0]辛烷和3-氧杂-1-杂氮杂双环[4.3.0]壬烷部分)是有效的催化剂。根据实验结果,尤其是氘标记研究,提出了一种合理的机理。