medicinal chemistry and organic synthesis is known. An efficient route to γ-keto sulfones through a metal-free reaction of cyclopropanols, sulfur dioxide and electron-deficient olefins is achieved. This reaction proceeds smoothly under mild conditions without the need of catalyst, oxidant or additive. A plausible mechanism is proposed, which undergoes through γ-keto sulfinate intermediate generated
Two-step conversion of carboxylic esters into distally fluorinated ketones via ring cleavage of cyclopropanol intermediates: application of sulfinate salts as fluoroalkylating reagents
作者:Yulia A. Konik、Marina Kudrjashova、Nele Konrad、Sandra Kaabel、Ivar Järving、Margus Lopp、Dzmitry G. Kananovich
DOI:10.1039/c7ob00680b
日期:——
used in the synthesis of distally fluorinated ketones. Cyclopropane ring cleavage reactions in methanol with aqueous tert-butyl hydroperoxide in the presence of a copper(II) acetate catalyst and sodium triflinate (Langlois reagent) afford β-trifluoromethyl ketones in 16–74% isolated yields. Sodium triflinate serves as a precursor of reactive trifluoromethyl copper species, enabling ring-opening trifluoromethylation
A route to γ-keto sulfones through a metal-free reaction of cyclopropanols, DABCO ⋅ (SO2)2 and alkyl halides is described. This reaction occurs under mild conditions in the absence of any catalysts, additives, or oxidants. Various functional groups including as ester, amino, methoxy, bromo, trifluoromethyl, nitro and carbonyl are tolerated well in this transformation, and the corresponding γ-keto sulfones
opening/alkynylation of cyclopropanol by employing inexpensive and commercially available terminal alkyne is developed. The reactions proceeded efficiently to afford synthetically useful alk-4-yn-1-ones in moderate to good yields with good functional group tolerance. Control experiments showed that the reaction presumably proceeds via the formation of intermediates of copper homoenolate and/or alkynylcopper
Rh-Catalyzed cascade C–H activation/C–C cleavage/cyclization of carboxylic acids with cyclopropanols
作者:Siqi Wang、Erfei Miao、Hao Wang、Bichao Song、Wei Huang、Weibo Yang
DOI:10.1039/d1cc01778k
日期:——
Merging both C–H and C–C activation in a tandemprocess is a marked challenge. A novel Rh(III)-catalyzed C–H activation/ring opening C–C cleavage/cyclization of carboxylic acids with cyclopropanols was developed for the synthesis of 3-substituted phthalides and α,β-butenolides. This reaction displays excellent functional group tolerance with respect to both carboxylic acids and cyclopropanols and features