Enhancement of the carbamate activation rate enabled syntheses of tetracyclic benzolactams: 8-oxoberbines and their 5- and 7-membered C-ring homologues
作者:Hiroaki Kurouchi
DOI:10.1039/d0ob02096f
日期:——
A route to the direct amidation of aromatic-ring-tethered N-carbamoyl tetrahydroisoquinoline substrates was developed. This route enabled general access to 8-oxoberberines and their 5- and 7- membered C-ring homologues. It overcomes the undesired tandem side-reactions that result in the destruction of the isoquinoline backbone, which inevitably occurred under our previously reported superacidic carbamate
A Method for Bischler–Napieralski-Type Synthesis of 3,4-Dihydroisoquinolines
作者:Lin Min、Weiguang Yang、Yunxiang Weng、Weiping Zheng、Xinyan Wang、Yuefei Hu
DOI:10.1021/acs.orglett.9b00534
日期:2019.4.19
s was developed by a Tf2O-promoted tandem annulation from phenylethanols and nitriles. Its success was mainly due to the fact that a phenonium ion was formed in the process and practically functioned as a stable and reactive primary phenylethyl carbocation.
Enantioselective, Copper-Catalyzed Alkynylation of Ketimines To Deliver Isoquinolines with α-Diaryl Tetrasubstituted Stereocenters
作者:Srimoyee Dasgupta、Jixin Liu、Clarissa A. Shoffler、Glenn P. A. Yap、Mary P. Watson
DOI:10.1021/acs.orglett.6b02787
日期:2016.12.2
An enantioselective, copper-catalyzedalkynylation of cyclic α,α-diaryl ketiminium ions has been developed to deliver isoquinoline products with diaryl, tetrasubstituted stereocenters. The success of this reaction relied on identification of Ph-PyBox as the optimal ligand, i-Pr2NEt as the base, and CHCl3 as the solvent. A broad scope and functional group tolerance were observed. Notably, the use of
An unusual solvent DMF-promoted dehydrogenation of 1-substituted 1,2,3,4-tetrahydroisoquinolines to synthesize cyclic imines is described. This environmentally friendly reaction features no requirement of any metal catalysts, oxidants, or hydrogenacceptors. A wide range of structurally varied 3,4-dihydroisoquinolines can be obtained with good yields and excellent chemoselectivities.