Catalytic Wittig and Mitsunobu reactions

摘要

A catalytic Wittig method utilizing a phosphine including the steps of providing a phosphine oxide precatalyst and reducing the phosphine oxide precatalyst to produce the phosphine; forming a phosphonium ylide precursor from the phosphine and a reactant; generating a phosphonium ylide from the phosphonium ylide precursor; reacting the phosphonium ylide precursor with the aldehyde, ketone, or ester to form the olefin and the phosphine oxide which then reenters the cycle. The invention is also directed to a Mitsunobu reaction catalytic in phosphine.

主权项

1. A one-pot catalytic Wittig method to form an olefin from an organohalide and an aldehyde or ketone comprising the steps:
a) providing i) the organohalide, ii) the aldehyde or ketone, iii) a phosphine oxide, and iv) a silane reducing agent; b) reducing the phosphine oxide with the silane reducing agent to produce a phosphine; c) forming a phosphonium ylide precursor with the phosphine and organohalide; d) generating a phosphonium ylide from the phosphonium ylide precursor; and e) reacting the phosphonium ylide with the aldehyde or ketone to form the olefin and said phosphine oxide;
wherein the phosphine oxide is selected from the group: wherein n is between 0 and 4; m is between 0 and 14; and R is an alkyl; R1, R2, and R3 are each an alkyl, aryl, alkoxy, or heteroaryl; and the organohalide is a primary or secondary organohalide.