Stoichiometric and Catalytic Conversion of Alkynes to Conjugated (<i>Z</i>,<i>Z</i>)-Dienes and Cyclopentadienes via Palladacyclopentadienes and 1,3-Dienylpalladium(II) Halide and Triorganopalladium(IV) Halide Compounds Containing Chelating Nitrogen Ligands
作者:Ruud van Belzen、René A. Klein、Huub Kooijman、Nora Veldman、Anthony L. Spek、Cornelis J. Elsevier
DOI:10.1021/om970977l
日期:1998.4.1
transmetalation with tetramethyltin, a catalytic cycle for the three-component synthesis of (Z,Z)-dienes of the type R−C(E)C(E)C(E)C(E)CH3 (8, R = alkyl, aryl; E = CO2CH3) has been conceived, e.g., from dimethyl 2-butynedioate, an organic halide, and tetramethyltin employing 1% of 1b as the catalyst in DMF. This constitutes the first catalytic synthesis of conjugated dienes from alkynes. Pd(phosphine) compounds
含有螯合双齿氮配体Pd (C(E)C(E)-C(E)C(E)}(NN)1a - f(E = CO 2 Me,NN =已从Pd(dba)2制备了Ph-bip,Ar-bian,bpy,dcm-bpy,bpym)和2a,b(E = CF 3,NN = Ph-bip,(p -tol)-bian),适当的双齿N-配体和缺电子的炔基2-丁炔二酸二甲酯或六氟丁炔,获得化合物1a(NN = Ph-bip)和1d(NN = 2,2'-bpy)的X射线晶体结构。溶液中,化合物1d的单体和二聚体之间存在平衡和1e(NN =联嘧啶); 在固态下,1d是单体。1d的二聚体形式与零价钯化合物[(μ-3,3'-二甲氧基-2,2'-联吡啶)Pd(tcne)] 2具有相同的类型,其中两个联吡啶衍生物桥接在两个钯之间由该化合物(7)的X射线晶体结构确定的中心。Palladacycles 1经历甲基碘,苄基溴或碘苯的氧化加成。随后的还原消除引起4官能的1