Superacid-catalyzed reactions of pyridinecarboxaldehydes
摘要:
A variety of pyridinecarboxaldehydes are shown to give condensation products in high yields (80-99%, 10 examples) by reacting with benzene and CF3SO3H (triflic acid). In the superacidic solution, pyridinecarboxaldehydes can react with deactivated arenes (o-dichlorobenzene and nitrobenzene) and with saturated hydrocarbons (methylcyclohexane and adamantane). Dicationic intermediates from pyridinecarboxaldehydes in superacid (FSO3H-SbF5) have been directly observed using low temperature C-13 NMR spectroscopy. Diprotonated pyridinecarboxaldehydes have also been studies using ab initio computational methods. (c) 2006 Elsevier Ltd. All rights reserved.
LDA-Mediated Synthesis of Triarylmethanes by Arylation of Diarylmethanes with Fluoroarenes at Room Temperature
作者:Xinfei Ji、Tao Huang、Wei Wu、Fang Liang、Song Cao
DOI:10.1021/acs.orglett.5b02602
日期:2015.10.16
A practical and convenient approach for the secondary C(sp(3))-H arylation of diarylmethanes with various fluoroarenes is described. The reaction proceeds smoothly in the presence of LDA (lithium diisopropylamide) at room temperature and affords triarylmethanes in moderate to high yields.