Catalytic Intramolecular Palladium-Ene Reactions. Preliminay Communication
作者:Wolfgang Oppolzer、Jean-Marc Gaudin
DOI:10.1002/hlca.19870700604
日期:1987.9.23
acetoxy-dienes 2 3 and 10 11 gave 1-vinyl-2-methylidene-subsituted cyclopentances and cyclohexanes in high yield, consistent with a palladium-ene/β-elimination mechanism (D E F, Scheme 2). The efficient and highly stereoselective cyclizations 7 7 and 8 9 illustrate intramolecular allylpalladium insertions into 1,2-dialkyl-, trialkyl-, trialkyl-, and cyclic alkenes followed by elimination of the exocyclic
Pd(dba)2 [dba =二亚苄基丙酮] / PPh 3-或Pd(PPh 3)4催化的乙酰氧基二烯2 3和10 11环化反应可高产率地得到1-乙烯基-2-亚甲基取代的环戊烯和环己烷,与钯-烯/β-消除机理(DEF,方案2)一致。高效且高度立体选择性的环化反应7 7和8 9举例说明了分子内烯丙基钯插入1,2-二烷基,三烷基,三烷基和环状烯烃中,然后消除环外β-H生成1,2-二乙烯基环戊烷的方法。这些新的烯烃插入在AcOH中(与THF相比)进行得更快,并且相对于Pd(13 14 15)优先出现顺式。