Phosphorus-Bearing Axially Chiral Biaryls by Catalytic Asymmetric Cross-Cyclotrimerization and a First Application in Asymmetric Hydrosilylation
作者:Barbara Heller、Andrey Gutnov、Christine Fischer、Hans-Joachim Drexler、Anke Spannenberg、Dmitry Redkin、Corinna Sundermann、Bernd Sundermann
DOI:10.1002/chem.200600826
日期:2007.1.22
two-step route to axially chiral biaryls is demonstrated. In a direct asymmetric cross-cyclotrimerization in the presence of a chiral cobalt(I) catalyst, axially chiral biaryls bearing phosphoryl moieties have been prepared, and through indirect evidence the authors have been able to clarify the origin of the stereochemical induction and the nature of the central intermediate in the catalytic cycle. By subsequent
证明了新颖且有效的两步法制备轴向手性联芳基。在手性钴(I)催化剂存在下的直接不对称交叉环三聚反应中,已经制备了带有磷酰基的轴向手性联芳基,并且通过间接证据,作者已经能够阐明立体化学诱导的起源和分子式的性质。催化循环中的中心中间体。通过随后将磷酰基部分还原成相应的膦,已经开发了非常有效且原子经济的手性体系方法。这些手性体系显然具有作为轴向手性单齿P-或双齿P,O-配体的巨大潜力,正如在不对称氢化硅烷化反应中采用新型NAPHEP作为新的单齿作用配体所证明的那样。