IMMOBILIZED ALDEHYDES AND OLEFINS IN THE SOLID SUPPORT SYNTHESIS OF TETRAHYDROQUINOLINES VIA A 3 COMPONENT CONDENSATION

Two novel and highly efficient solid support (SS) versions of tetrahyd roquinoline synthesis based on the three component condensation reacti on of aldehydes, anilines, and electron-rich olefins catalyzed by trif luoroacetic acid were described. In the first version, 4-carboxybenzal dehyde was immobilized on Acid sensitive MEthoxy BenzAldehyde (AMEBA) resin as the solid-supported component of this reaction. The procedure provided tetrahydroquinolines in high yield (60-87%) and good purity (>80%). Further advancement of this solid-phase synthesis was achieved by using resin-bound olefins (prepared from immobilized 4-hydroxybenz aldehyde, and the corresponding Wittig reagents) with anilines, and al dehydes to afford the target products (61-85% yields, >85% purity). Bo th SS approaches allowed the use of novel alkene, aniline, and aldehyd e entries, thereby yielding a diverse array of tetrahydroquinolines. ( C) 1998 Elsevier Science Ltd. All rights reserved.