DEATMS (Et_2NTMS)を用いるアルデヒドの直接的求核反応

概要

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Unmodified aldehydes directly add in 1, 4-manner to electron deficient olefins in the presence of a catalytic amount of diethylaminotrimethylsilane (DEATMS) in acetonitrile. Work up procedure was so simple that evacuation under reduced pressure followed by liquid chromatography or bulb to bulb distillation of the residue provided the products. Reaction of aldehydes with methyl α-haloacrylates generated <I>in situ</I> from methyl 2, 3-dihalopropanoates by DEATMS provided formylcyclopropanecarboxylates by domino conjugate addition-alkylation. Self- or cross-aldol con-densation of aldehydes afforded unsaturated aldehydes. The reaction was revealed to proceed via catalytic enamine pathway. The conjugate addition was also catalyzed by diethylamine or amine grafted on solid support in conventional organic solvent as well as ionic liquid, in which recycle of the solvent and the catalyst was realized.<BR>Total syntheses of several bisabolane type sesquiterpenoids, (+) / (-) -a-bisabol-1-one, (-) - curcumene, (-) -curcuphenol, and (+) / (-) -elvirol have been accomplished starting from 5-ketoaldehydes prepared by 1, 4-conjugate addition of unmodified aldehydes to vinylketones employing citronellal as a chiral source.
社団法人有機合成化学協会の論文
2002-10-01