已经制备了一系列的1-取代的2,2,3,4,4-五甲基膦酸酯,并且在用六氟丙酮处理后将其转化为相应的1,3,2-二氧杂膦酸酯。这些加合物在一定温度范围内的19 F nmr光谱给出了伪旋转过程的活化自由能值,该伪旋转过程使四元环二甲基吡咯和1位取代基位于顶峰。在与1-取代基的性质这些活化能的变化在组既是电负性和的函数的相对apicophilicity方面占p π - d π背键。探索了该假设的一些后果。描述了1,3,2-二氧杂磷杂环戊烷和相关的1,2-氧杂磷杂环戊烷的一些不寻常的反应和异构化。
Enantioselective Deprotonation as a Vehicle for the Asymmetric Synthesis of C2-Symmetric P-Chiral Diphosphines
作者:Alexander R. Muci、Kevin R. Campos、David A. Evans
DOI:10.1021/ja00140a028
日期:1995.9
Communication is to disclose a convenient approach to the synthesis of Cz-symmetric P-chiral diphosphines4 that relies upon successive enantioselectivedeprotonation of aryldimethylphosphine-boranes or aryldimethylphosphine sulfides (eq 1) and subsequent oxidative coupling to the diphosphine precursors (eq 2) with high overall enantioselectivity (296%) for the two-step process.