- An expedient synthesis of cyanoformates via DAST-mediated C–C bond cleavage of α-oximino-β-ketoesters
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A new protocol to synthesize cyanoformates was developed using simple β-ketoesters as substrates. (Diethylamino)sulfur trifluoride (DAST) was used as a dual-role reagent to activate the oxime moiety and to donate a fluoride. The key intermediates, α-oximino-β-ketoesters, were prepared by highly efficient acid-assisted oximation of β-ketoesters. Then, the deconstruction of α-oximino-β-ketoesters by the fluorinative C–C bond cleavage was demonstrated to provide cyanoformates. In this event, the fluoride addition followed by the C–C bond cleavage selectively occurred in the ketones over esters. Due to simple and mild reaction conditions, variously functionalized cyanoformates were exemplified.
- Kim, Danhee,Lim, Hee Nam
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supporting information
(2021/05/10)
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- Direct Synthesis of Tri-/Difluoromethyl Ketones from Carboxylic Acids by Cross-Coupling with Acyloxyphosphonium Ions
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A simple and straightforward approach to the synthesis of trifluoromethyl and difluoromethyl ketones from widely available carboxylic acids is disclosed. The transformation utilizes an acyloxyphosphonium ion as the active electrophile, conveniently generated in situ from the carboxylic acid substrate by using commodity chemicals. The utility of the reaction system is exemplified by its chemoselectivity, with tolerance to a variety of important functional groups. The late-stage functionalization of carboxylic acid active pharmaceutical ingredients and pharmaceutically relevant compounds is also discussed.
- Ispizua-Rodriguez, Xanath,Munoz, Socrates B.,Krishnamurti, Vinayak,Mathew, Thomas,Prakash
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supporting information
p. 15908 - 15913
(2021/10/07)
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