Gold(I)/(III)-catalyzed synthesis of 2-substituted piperidines; valency-controlled cyclization modes
作者:Nobuyoshi Morita、Tomonori Tsunokake、Yuji Narikiyo、Mayuka Harada、Tatsuyuki Tachibana、Yuta Saito、Shintaro Ban、Yoshimitsu Hashimoto、Iwao Okamoto、Osamu Tamura
DOI:10.1016/j.tetlet.2015.09.115
日期:2015.11
Strategic use of hard gold(III) and soft gold(I) catalysts provides facile access to two types of 2-substituted piperidines from propargylic alcohols. Thus, heating propargylic alcohols in the presence of AuBr3 results in cyclization to furnish piperidines having an acetylenic moiety, due to activation of the propargylic hydroxyl group by coordination of gold(III). On the other hand, the catalyst [Ph3PAuNTf2]2PhMe
战略性地使用硬金(III)和软金(I)催化剂可以轻松地从炔丙醇制得两种类型的2-取代的哌啶。因此,在AuBr 3存在下加热炔丙醇导致环化以提供具有炔部分的哌啶,这是由于通过金(III)的配位活化了炔丙羟基。另一方面,催化剂[Ph 3 PAuNTf 2 ] 2 PhMe引起炔丙醇的Meyer-Schuster重排,得到α,β-不饱和酮,由于活化,分子内的氮杂-Michael加成后可提供带有羰基的哌啶通过金(I)的配位形成三键。