- METHOD FOR THE MANUFACTURE OF ALKOXYSILYL-CONTAINING THIOCARBOXYLIC ACID ESTERS
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There is provided herein a method for the manufacture of alkoxysilyl-containing thiocarboxylic acid ester which comprises reacting a thioester with a mercapto-functional alkoxy silane and/or an alkali metal salt, an alkaline earth metal salt, a trisubstituted ammonium salt of an alkoxysilyl-functional thiolate which uses economical and readily available reagents, avoids the use of phosgene or thionyl chloride reagents and produces byproducts that may be recycled.
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Page/Page column 33-34; 35
(2020/11/12)
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- One for Many: A Universal Reagent for Acylation Processes
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This work describes acylation reactions facilitated by a type of heterocycle-based acyl transfer agent, 2-acyloxypyridazinone. Reactions of 2-acyloxypyridazinone with carboxylic acids yield mixed carbonic anhydride intermediates, which are reactive and could be coupled with a wide range of substrates including acids, amines, alcohols, and thiols. The wide substrate scope, ease of operation (no additive or catalyst), storage and handling stability, and atom-efficiency from recycling the heterocycle carrier make the reported acylating agent attractive for acylation-based coupling reactions.
- Moon, Hyun Kyung,Sung, Gi Hyeon,Kim, Bo Ram,Park, Jong Keun,Yoon, Yong-Jin,Yoon, Hyo Jae
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supporting information
p. 1725 - 1730
(2016/06/09)
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- Lipase chemoselectivity towards alcohol and thiol acyl acceptors in a transacylation reaction
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The lipase chemoselectivity towards an alcohol and a thiol was investigated for the two lipases Candida antarctica lipase B (CalB) and Rhizomucor miehei lipase (Rml). Hexanol and hexanethiol were used as acyl acceptors in a transacylation reaction with ethyl octanoate in cyclohexane. CalB showed the highest chemoselectivity ratio (kcat/KM) OH/(kcat/KM)SH, of 88,000 while the ratio for Rml was 1200. That could be compared with the ratio, k OH/kSH, of 120 for the non-catalyzed reaction. Thus, the enzyme contribution to the chemoselectivity between hexanol and hexanethiol was 730 for CalB and 10 for Rml. High KM values displayed towards hexanethiol (above 1.8 M) were the largest contribution to the selectivity. No saturation was achieved. The KM values were more than two orders of magnitude higher than those of hexanol.
- Hedfors, Cecilia,Hult, Karl,Martinelle, Mats
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experimental part
p. 120 - 123
(2010/12/19)
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