Diprotonative stabilization of ring-opened carbocationic intermediates: conversion of tetrahydroisoquinoline to triarylmethanes
作者:Hiroaki Kurouchi
DOI:10.1039/d0cc01969k
日期:——
Superacid-promoted conversion of tetrahydroisoquinolines to triarylmethanes via tandem reactions of C–N bond scission, Friedel–Crafts alkylation, C–O bond scission, and electrophilic aromatic amidation was developed. Dication formation was important for stabilizing the ring-opened carbocationic intermediate, which is a new role for diprotonation in reaction mechanisms.
were allowed to react with a nucleophile (silyl enol ether or allyltributyltin) in the presence of an acyl chloride derivedfrom (S)-alanine to afford the 1,2-addition products in good chemical yields and high stereoselectivity. The bromo groups were readily removed by a reduction process in which the double bond at C3–C4 was also reduced. Thus the reaction system provided a general method to synthesize
Dipole stabilized α-amino carbanions. II. Alkylation of tetrahydroisoquinolines in the 1-position.
作者:A.I. Meyers、Stuart Hellring、Wolter Ten Hoeve
DOI:10.1016/s0040-4039(01)92434-7
日期:1981.1
N-Formamidine derivatives of tetrahydroisoquinolines are metalated and alkylated to give 1-substituted derivatives. Regeneration of the parent amine is accomplished by several different reagents.
A metal-free cross-dehydrogenative coupling of N-carbamoyl tetrahydroisoquinoline with a variety of C-H nucleophiles mediated by Na2S2O8 is developed. The reaction proceeds smoothly to give the coupled product in up to 83% yields. The nucleophile scope is broad, including simple ketones, aldehydes, and aryl rings. The carbamoyl protecting group can be readily removed under mild condition. The use of Na2S2O8 as the sole reagent for the CDC reaction is attractive based on economical and environmental factors. (C) 2014 Elsevier Ltd. All rights reserved.
PIRKLE, W. H.;WELCH, CH. J.;MAHLER, G. S.;MEYERS, A. I.;FUENTES, L. M.;BO+, J. ORG. CHEM., 1984, 49, N 13, 2504-2506
作者:PIRKLE, W. H.、WELCH, CH. J.、MAHLER, G. S.、MEYERS, A. I.、FUENTES, L. M.、BO+