Photosensitized electron transfer catalysis of the Mukaiyama aldol reaction by monocationic N-21,N-22-bridged porphyrins

摘要

N-21,N-22-Bridged porphyrin hydroperchlorates were converted into monocationic N-21,N-22-bridged N-23-alkylphlorins by way of single electron transfer followed by radical coupling when irradiated with visible light in the presence of enol silanes. A small amount (0.13 mol %) of N-21,N-22-bridged porphyrin hydroperchlorates catalyzed aldol reaction of aldehydes and ketones with enol silanes under the irradiation of visible light. The phlorin intermediate plays a by role in this photosensitized catalysis of the Mukaiyama aldol reactions. (C) 1999 Elsevier Science Ltd. All rights reserved. [References: 27]