A Mechanistic Study concerning the Carbon-Silicon Bond Cleavage in Acylsilane Bioreductions

Abstract

Some mechanistic proposals are made for the competitive desilylation reactions affording the corresponding primary alcohol and carboxylic acid that frequently occur in the bioreduction of acylsilanes.

Acylsilanes and their applications in organic chemistry

“…The disadvantage in using acylsilane bioreductions is the required lengthy period of reaction, which generally leads to the formation of by-products such as primary alcohols and carboxylic acids from C-Si bond cleavage. A radical oxidation of acylsilanes seems to be responsible for the formation of carboxylic acids 81 In Scheme 50 there is an interesting example of the bioreduction of a racemic acylsilane (±)-123 containing asymmetric silicon that was applied to afford chiral silyl compounds. Thus, acylsilane (-)-123, prepared by oxidation of (+)-124, was treated with phenyllithium, the asymmetric silyl group being a chiral inductor.…”

Theoretical investigation of the reaction of dialkylzincs with α-alkoxycarbonyl radicals. Evaluation of α-bromoacrylates as radical acceptors in radical-polar crossover processes

“…All melting points are uncorrected; they were recorded in open capillary tubes using melting points apparatus. 2-Bromo-acrylic acid ethyl ester (1) 43 and benzoyltrimethylsilane 44 were prepared according to known procedures. Acetyltrimethylsilane is commercially available and it was used without additional purification.…”

Syntheses of 2-Formyl-, 2,3-Diformyl- and 8-Formyl-1-azaazulenes

“…It is thought that introduction of 1,3-dithian-2-yl group, being a synthetic equivalent of formyl group, would be an excellent method. [19][20][21][22][23][24][25][26][27][28] Therefore, the reaction of 2-lithio-1,3-dithine with 1-azaazulenes and successive hydrolysis was examined.…”

“…22,23 Thus treatment of 12a with an equivalent of NBS in the presence of DMSO in chloroform at rt for 16 h gave 13b in 36% yield. Same product (13b) was obtained by the reaction of 12b with 0.2 equivalent of NBS in the presence of DMSO in chloroform at rt for 26 h in 58% yield.…”