Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles-CNRS UPR 2301, 1, av. de la Terrasse, 91198 Gif-sur-Yvette Cedex, France.
Chemistry. 2010 Jan 18;16(3):1033-45. doi: 10.1002/chem.200901893.
The planar chiral 2-phospha[3]ferrocenophane I has been shown to be the first efficient nucleophilic organocatalyst for the enantioselective synthesis of cyclopentenylphosphonates, through [3+2] cyclizations between diethyl allenylphosphonate and alpha,beta-unsaturated ketones. The same catalyst has also been applied to the highly enantioselective [3+2] cyclizations of allenic esters with dibenzylideneacetone and analogous bis-enones, leading to functionalised cyclopentenes with either monocyclic or spirocyclic structures (ee 84-95 %). It has been shown that the residual enone functions in the resulting cyclopentenes can be involved in subsequent cyclization steps to afford unprecedented C(2)-symmetric bis-cyclopentenylketones. In order to provide insight into the behaviour of FerroPHANE I as a chiral catalyst in [3+2] cyclisations, the energetically most favoured isomers of the key phosphine-allene adduct have been calculated by DFT methods. Factors likely to control the chiral induction process are highlighted.
平面手性 2-膦[3]费罗芬烷 I 已被证明是通过二乙基烯丙基膦酸盐与α，β-不饱和酮之间的[3+2]环化反应，用于手性选择性合成环戊烯基膦酸酯的第一种有效亲核有机催化剂。相同的催化剂也已应用于烯丙基酯与二亚苄基丙酮和类似的双烯酮的高度对映选择性[3+2]环化反应，得到具有单环或螺环结构的官能化环戊烯（ee84-95%）。已经表明，所得环戊烯中残留的烯酮官能团可以参与随后的环化步骤，从而提供前所未有的 C（2）对称双环戊烯基酮。为了深入了解 FerroPHANE I 在手性催化剂[3+2]环化反应中的行为，通过 DFT 方法计算了关键的膦-烯丙基加合物的能量上最有利的异构体。突出了可能控制手性诱导过程的因素。
