Terminal Alkyne Coupling Reactions Through a Ring: Effect of Ring Size on Rate and Regioselectivity
作者:Caroline M. Storey、Matthew R. Gyton、Rhiann E. Andrew、Adrian B. Chaplin
DOI:10.1002/chem.202002962
日期:2020.11.17
alkynyl alkenyl derivatives and produce rhodium(I) complexes of conjugated 1,3‐enynes by C−C bond reductive elimination through the annulus of the ancillary ligand. The intermediates are formed with orthogonal regioselectivity, with E‐alkenyl complexes derived from HC≡CtBu and gem‐alkenyl complexes derived from HC≡CAr’, and the reductive elimination step is appreciably affected by the ring size of the
由基于大环 NHC 的钳形配体的铑 (I) 配合物促进的末端炔烃偶联反应,其特征是十二亚甲基、十四亚甲基或十六亚甲基翼尖连接体,即。[Rh(CNC-n)(C 2 H 4 )][BAr F 4 ] (n=12, 14, 16; Ar F =3,5-(CF 3 ) 2 C 6 H 3 )—已被研究,使用大炔烃 HC≡C t Bu 和 HC≡CAr' (Ar'=3,5‐ t Bu 2 C 6 H 3 ) 作为底物。这些化学计量反应继续形成铑(III)炔基烯基衍生物,并通过辅助配体的环通过CC键还原消除产生共轭1,3-烯炔的铑(I)络合物。中间体以正交区域选择性形成,其中E-烯基配合物衍生自HC≡C t Bu,gem-烯基配合物衍生自HC≡CAr',并且还原消除步骤明显受到大环环尺寸的影响。对于 HC−C t Bu的自偶联,E ‐ t BuC−CCH=CH t Bu 是通过相应的铑 (III) 炔基E