Collect. Czech. Chem. Commun.
1999, 64, 829-846
https://doi.org/10.1135/cccc19990829
Novel Addition and [3+2] Cycloaddition Reactions of Stannyl- and Silyl-ortho-carboranes to Carbonyl Compounds
Hiroyuki Nakamura and Yoshinori Yamamoto*
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Abstract
Stannyl- and silyl-ortho-carboranes serve as an ortho-carborane carbanion equivalents in the addition reaction to aldehydes. The reaction of (tributylstannyl)-ortho-carborane 2 with aldehydes 4 in the presence of palladium(0) catalysts gave the corresponding (ortho-carboranyl) carbinols 5 in good to high yields. The reaction of (trimethylsilyl)-ortho-carborane 3 with aldehydes 4 in the presence of tetrabutylammonium fluoride (TBAF) gave the corresponding (ortho-carboranyl) carbinols 5 in high yields. Furthermore, (trimethylsilyl)-ortho-carborane 3 underwent a facile [3+2] annulation reaction with various α,β-unsaturated enals and enones in the presence of tetrabutylammonium fluoride, giving the corresponding five-membered carboracyclic products 14 in good to high yields.
Keywords: Additions; ortho-Carborane; Palladium catalysis; Carbonyl compounds; [3+2] Annulations; Carboranes; Stannanes; Silanes; Boron neutron capture therapy.
