3-dithianes using 30% hydrogen peroxide catalyzed by iron(III) acetylacetonate–sodium iodide. The use of niobium(V) chloride as a catalyst instead of iron(III) acetylacetonate was also effective, except in synthesizing some acyltrimethylsilanes. Acylsilanes were obtained efficiently from dedithioacetalization of 2-silylated 1,3-dithianes using 30% hydrogen peroxide catalyzed by iron(III) acetylacetonate–sodium
Intermolecular carbon-carbon bond formation between acylsilanes and organoboronic esters was achieved by photoirradiation under almost neutral, transition metal-free conditions. In this reaction, siloxycarbenes generated by photoisomerization of acylsilanes reacted with boronic esters to give the formal B-C bond insertion intermediates, which underwent unique rearrangement to afford the cyclic alpha-alkoxyboronic esters. Acidic treatment of the resulting crude products under air furnished the cross-coupled ketones in good yields.
Synthesis of acylsilanes via oxidative hydrolysis of 2-silyl-1,3-dithianes mediated by N-bromosuccinimide
作者:Amauri F Patrocı́nio、Paulo J.S Moran
DOI:10.1016/s0022-328x(00)00181-9
日期:2000.5
The oxidative method for the hydrolysis of 1,3-dithianes was applied to 2-silyl-1,3-dithianes using N-bromosuccinimide providing acylsilanes with good yields under a short reaction period. The oxidation of aroylsilanes to carboxylic acid was prevented by the addition of bases and the lowering of the reaction temperature. (C) 2000 Elsevier Science S.A. All rights reserved.