Alkene Metatheses in Transition Metal Coordination Spheres: Effect of Ring Size and Substitution on the Efficiencies of Macrocyclizations That Join <i>trans</i> Positions of Square-Planar Platinum Complexes
作者:Eike B. Bauer、Frank Hampel、J. A. Gladysz
DOI:10.1021/om034121u
日期:2003.12.1
Br(CH2)nCHCH2 give the phosphines PPh2(CH2)nCHCH2 (n = a, 4; b, 6; c, 8; d, 9; 95−41%), which are combined with the platinum tetrahydrothiophene complex [Pt(μ-Cl)(C6F5)(S(CH2CH2−)2)]2 to give trans-(Cl)(C6F5)Pt(PPh2(CH2)nCHCH2)2 (3a−d, 71−54%). When treated with Grubbs' catalyst, ring-closing alkene metatheses occur to give 13- to 23-membered macrocycles with trans-spanning diphosphine ligands (96−85%
KPPh 2与Br(CH 2)n CH CH 2的反应生成膦PPh 2(CH 2)n CH CH 2(n = a,4; b,6; c,8; d,9; 95-41% ),将其与四氢噻吩铂配合物[Pt(μ-Cl)(C 6 F 5)(S(CH 2 CH 2-)2)] 2合并,得到反式-(Cl)(C 6 F 5)Pt (PPh2(CH 2)n CH CH 2)2(3a - d,71-54%)。当用格鲁布斯的催化剂处理时,会发生闭环烯烃复分解反应,生成具有跨跨二膦配体(96-85%,包括一些二聚或低聚副产物)的13至23元大环。将C C异构体的混合物加氢(1 atm,10%Pd / C)得到(6a - d),将其分离出来,产率为72-50%。使用(1)第二代二氢咪唑基亚基Grubbs催化剂和(2)衍生自二甲基化膦Ph 2的一系列化合物可获得可比的结果。P(CH 2)2 C(CH 3)2(CH 2)3