Oxidative nitroalkylation of β-ketoamides and nitroalkanes, mediated by hypoiodide generated from tert-butyl hydrogen peroxide and a catalytic amount of guanidinium iodide, afforded the corresponding α-nitroalkyl-β-ketoamides in up to 97% yield.
Highly Selective Difluoromethylations of β-Keto Amides with TMSCF2Br under Mild Conditions
作者:Yakun Wang、Shuaifei Wang、Conghui Zhang、Ting Zhao、Yanqin Hu、Mingwei Zhang、Pengli Chen、Yang Fu
DOI:10.1055/a-1507-5878
日期:2021.7
Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under mild conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high carbon/oxygen (C/O) regioselectivities (up to 99:1). The C/O selectivity of β-keto
By using a readily accessible, new and safe cyano-transfer reagent, 1-cyanato-4-nitrobenzene, the enantioselectivity of the direct electrophilic α-cyanation of 1-indanone-derived β-keto amides was greatly improved as a result of an enhanced double-hydrogen bonding. Thus, in the presence of cinchonine as the bifunctional organocatalyst, a series of α-cyano β-keto amides were produced in excellent yields
Construction of Complex 1,3-Cyclohexadienes via Phosphine-Catalyzed (4 + 2) Annulations of δ-Acetoxy Allenoates and Ketones
作者:Yuwen Zhang、Xiaofeng Tong
DOI:10.1021/acs.orglett.7b02787
日期:2017.10.6
The phosphine-catalyzed substrate-dependent (4 + 2) annulations of δ-acetoxy allenoates with ketones is described. Allenoates 1 with an alkyl substituent at δC are able to react with cyclic 1,3-diketones 2, wherein the δC is attacked by the methenyl carbon of 2 while the αC attacks the ketone of 2. Allenoates 5 with an aryl group at δC is poised to react with cyclic β-carbonyl amides 6, in which the