1,2,3-triazole-linked dendrimers as a support for functionalized and recoverable catalysts for asymmetric borane reduction of prochiral ketones

A series of new, functionalized, and chiral catalysts have been synthesized based on 1,2,3-triazole-linked dendrimers. It has been found that dendrimer 7f is an efficient catalyst for the enantio selective borane reduction of both electron-deficient and electron-rich ketones, and high enantioselectivities were obtained (up to 96%). The catalyst can be recovered and reused four times without a significant loss of catalytic activity. (C) 2008 Elsevier Ltd. All rights reserved.