Highly Regio- and Chemoselective [2 + 2 + 2] Cycloaddition of Electron-Deficient Diynes with Allenes Catalyzed by Nickel Complexes: A Novel Entry to Polysubstituted Benzene Derivatives
作者:Muthian Shanmugasundaram、Ming-Si Wu、Masilamani Jeganmohan、Chih-Wei Huang、Chien-Hong Cheng
DOI:10.1021/jo0203084
日期:2002.11.1
Diynes 1a-c [X(CH(2)Ctbd1;CCO(2)Me)(2): X = (CH(2))(2), 1a, X = CH(2), 1b and X = O, 1c] undergo [2 + 2 + 2] ene-diyne cycloaddition reactions with a variety of allenes (n-butylallene 2a, phenylallene 2b, (4-chlorophenyl)allene 2c, (4-bromophenyl)allene 2d, (3-methoxyphenyl)allene 2e, 1-naphthylallene 2f, cyclohexylallene 2g and cyclopentylallene 2h) in the presence of Ni(dppe)Br(2) and Zn powder in
Diynes 1a-c [X(CH(2)Ctbd1; CCO(2)Me)(2):X =(CH(2))(2),1a,X = CH(2),1b和X = O, 1c]与各种丙二烯(正丁基丙二烯2a,苯丙二烯2b,(4-氯苯基)丙二烯2c,(4-溴苯基)丙二烯2d,(3-甲氧基苯基)]进行[2 + 2 + 2]烯-二炔环加成反应Ni(dppe)Br(2)和Zn粉在CH(3)CN中在80°C下存在8h的条件下,在8h的条件下,在8°C的条件下,在8°C的条件下,在80°C的条件下将8h的烯丙基2e,1-萘烯丙基2f,环己烯丙基2g和环戊烯丙基2h) -l的产量好到极好。在相似的反应条件下,不对称二炔5a-c(HCtbd1; CCH(2)XCH(2)Ctbd1; CCO(2)Me)与丙二烯2反应,以73-86%的收率独家提供相应的间位异构体6a-g 。催化反应具有高度的区域选择性和完全的化学选择性。该