Aryl trialkylsilyl ketenes: Acid-catalyzed synthesis from 1-aryl-2-diazo-2-trialkylsilylethanones and their conversion into 3-silyl-1-silyloxyallenes

作者：Bucher Stefan M; Brueckmann Ralf; Maas Gerhard^*

来源：European Journal of Organic Chemistry, 2008, (26): 4426-4433.

DOI：10.1002/ejoc.200800524

• allenes
• diazo compounds
• ketenes
• rearrangement
• silylation

Aryl-substituted alpha-silyl alpha-diazo ketones are readily transformed into aryl silyl ketenes in the presence of a catalytic amount of triflic acid. Thus, a convenient method to prepare these silyl ketenes becomes available, which combines two steps, silylation of an aryl diazomethyl ketone and acid-induced Wolff rearrangement of the formed a-silyl a-diazo ketone, in a one-pot procedure. It appears that the trialkyl-ammonium salt, which is formed in the silylation step, can also catalyze the Wolff rearrangement, but distinctly more slowly than the proton acid. The silyl ketenes react smoothly with alpha-silyl alpha-diazo ketones to form 3-silyl-1-silyloxyallenes in fairly good yields.

• 出版日期2008-9