Reaction of 2-Hydroxybenzaldehydes with Alkynes, Alkenes, or Allenes via Cleavage of the Aldehyde C–H Bond Using a Rhodium Catalyst System
作者:Ken Kokubo、Kenji Matsumasa、Yuko Nishinaka、Masahiro Miura、Masakatsu Nomura
DOI:10.1246/bcsj.72.303
日期:1999.2
2-Hydroxybenzaldehydes smoothly and efficiently react with various internal and terminal alkynes accompanied by cleavage of the aldehyde C–H bond by using a rhodium-based catalyst system of [RhCl(cod)]2/dppf/Na2CO3 [cod = 1,5-cyclooctadiene; dppf = 1,1′-bis(diphenylphosphino)ferrocene] to give the corresponding 2-alkenoylphenols in good to excellent yields. The regioselectivity of the reaction depends on the substituents of acetylene; an oxygen function on the propargylic position shows a considerable directing effect. The aldehydes can also react with some alkenes or allenes, such as triethylvinylsilane and 2-norbornene or 3-methyl-1,2-butadiene and 1,2-nonadienes, in place of alkynes.
2-羟基苯甲醛通过使用铑基催化剂体系[RhCl(cod)]2/dppf/Na2CO3(cod = 1,5-环辛二烯;dppf = 1,1'-双(二苯基膦)二茂铁),顺利且高效地与各种内端炔烃反应,伴随着醛基C-H键的断裂,得到相应的2-烯酰基苯酚,产率良好至优秀。反应的区域选择性取决于乙炔上的取代基;丙炔位上的氧功能显示出显著的导向作用。这些醛类还能与某些烯烃或Allenes反应,如三乙基乙烯基硅烷和2-降冰片烯或3-甲基-1,2-丁二烯和1,2-壬二烯,替代炔烃。