Decarboxylation-based traceless linking with aroyl acrylic acids

beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition of indolines have been performed.

Upon cleavage, the products are decarboxylated, and the beta-indolinyl propiophenones are isolated. The reaction conditions have been optimized, and a small library has been prepared. (C) 1998 Elsevier Science Ltd. All rights reserved.