Synthesis of Chiral Thienylpyridines from Naturally Occurring Monoterpenes: Useful Ligands for Cyclometallated Complexes
作者:Michel Gianini、Alex von Zelewsky
DOI:10.1055/s-1996-4280
日期:1996.6
On treatment with ammonium acetate, α,β-unsaturated ketones or aldehydes can easily undergo condensation with acetylpyridinium salts (Kröhnke reaction). Four ”thienylpyridine” ligands, derived from (-)-β-pinene, (+)-camphor, (+)-3-carene and (+)-2-carene, were prepared according to this method. The multistep syntheses to get (1R,5R)-3-methyleneopinone (5), (+)-3-methylenecamphor (10), (-)-3-caren-10-al (15) and (1S,6R)-7,7-dimethyl-3-methylenebicyclo[4.1.0]heptan-2-one (18) are also described.
经醋酸铵处理后,δ,δ-不饱和酮或醛很容易与乙酰基吡啶鎓盐发生缩合反应(克伦克反应)。根据这种方法制备了四种 "噻吩基吡啶 "配体,它们分别来自(-)-δ-蒎烯、(+)-樟脑、(+)-3-蒈烯和(+)-2-蒈烯。此外,还介绍了获得 (1R,5R)-3-亚甲基蒎酮 (5)、(+)-3-亚甲基樟脑 (10)、(-)-3-蒈烯-10-al (15) 和 (1S,6R)-7,7-二甲基-3-亚甲基双环[4.1.0]庚-2-酮 (18) 的多步合成方法。