Coenzyme-inspired chemistry 2: 4,5-dihydroimidazolium ylides (NHCs) and the reactions of 2-(1-hydroxyalkyl)-4,5-dihydroimidazoles
作者:Raymond C. F. Jones、John R. Nichols
DOI:10.1039/c3ob40884a
日期:——
Ketones are prepared from aldehydes via 1-benzyl-2-(1-hydroxyalkyl)-4,5-dihydroimidazoles (adducts of the aldehydes with 1-benzyl-2-lithio-4,5-dihydroimidazoles) whereas 1-benzyl-2-(1-oxoalkyl)-4,5-dihydroimidazoles are shown to act as acyl transfer reagents via C–C bond cleavage. 4,5-Dihydroimidazolium ylides (NHCs) are intermediates in both processes, which constitute thiamine-inspired C–C bond formation and cleavage protocols.
酮是由醛通过1-苄基-2-(1-羟基烷基)-4,5-二氢咪唑(醛与1-苄基-2-锂-4,5-二氢咪唑的加合物)制备而成,而1-苄基-2-(1-氧代烷基)-4,5-二氢咪唑被证明是通过C–C键断裂的酰基转移试剂。4,5-二氢咪唑鎓叶立德(NHCs)在这两种过程中都是中间体,它们构成了受硫胺素启发的C–C键形成和断裂协议。