查看更多>>摘要：An efficient metal-free approach to access in situ generated tosyldiazomethane (TsDAM) and (Z)-aurones containing pyrazoles under mild conditions has been developed. This methodology involves 1,3-dipolar cycloaddition in an aqueous system, followed by an aromatization with a CAO bond cleavage in an acidic separation environment. We observed good yields under mild conditions, along with synthetic versatility and high functional group compatibility. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：An efficient catalyst-free direct nitration of the C-H bonds of tertiary beta-keto esters using tert-butyl nitrite as a nitrating reagent is described. This radical nitration protocol tolerants diverse functional groups, leading to the preparation of linear and cyclic alpha-nitro-beta-keto ester derivatives in good to excellent yields under mild conditions. In addition, the nitration product 3a was applied to the concise synthesis of a quaternary alpha-amino acid 4 in the presence of zinc power and acetic acid. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A weak Bronsted base-promoted photoredox catalysis has been developed for the direct C-H alpha-alkyla-tion of heteroarenes with cyclic and acyclic ethers. The high efficiency of this strategy is demonstrated by the mild reaction conditions, broad substrate scope, economical reagents and high regioselectivity. With air as the sole oxidant, a set of alkylated heteroarenes were accessed smoothly. This strategy was also applied for late-stage functionalization of valuable vitamin E nicotinate and loratadine. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A copper-catalyzed oxidative cross-dehydrogenative coupling (CDC) strategy of secondary phosphine oxides and alcohols for the synthesis of various phosphinate esters was proposed. Under the mild reaction conditions (CuCl2 center dot 2H(2)O/K2S2O8, at room temperature for 3-12 h under air), a variety of substrates were well-tolerated and afforded the desirable compounds in moderate to excellent yields. (C) 2022 Elsevier Ltd. All rights reserved.
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