Development of New Reactions with Organometallic Reagents Stable in

醛与有机金属试剂的烷基化反应是有机化学中最重要的反应之一。传统的烷基硼烷试剂不与醛反应。我们发现，在η^2-烯- 1,1,2,3,4,5 -五甲基- 1,1,3 -环戊二烯的催化量或过量的碳酸铯的存在下，镍催化醛与三烷基硼烷的烷基化反应顺利进行。硼烷-二甲基硫醚和末端烯烃经硼氢化反应制备的三烷基硼烷以及市售的三烷基硼烷均可用于该反应。该反应将通过12配位镍配合物进行，并以醛为关键中间体。有趣的是，水使醛与三烷基硼烷在镍催化下无添加剂的烷基化。

The alkylation of aldehydes with organometallic reagents is one of the most important reactions in organic chemistry. Conventional alkylborane reagents do not react with aldehydes. We disclosed that nickel-catalyzed alkylation of aldehydes with trialkylboranes proceeds smoothly in the presence of a catalytic amount of η^2-ally1-1,2,3,4,5-pentamethy1-1,3-cyclopentadiene or an excess of cesium carbonate to afford the corresponding secondary alcohols. Trialkylboranes prepared from borane-dimethyl sulfide and terminal olefins via hydroboration as well as commercially available trialkylboranes could be employed for the reaction. The reaction would proceed via 12-coordinated nickel complexes with aldehydes as key intermediates. Interestingly, water enabled alkylation of aldehydes with trialkylboranes under nickel catalysis without additives.