Divergent Functionalization of Alkynes Enabled by Organic Photoredox Catalysis
作者:David A. Nicewicz、Zhengbo Zhu、Siran Qian
DOI:10.1055/a-2009-8279
日期:——
oxidative conditions is challenging, as alkynes are usually recalcitrant towards typical oxidants. Herein, we communicate a strategy for the divergent functionalization of alkynes with photoexcited acridinium organic dyes, presumably via the formation of vinyl cation radicals as key intermediates. Based on the nature of the nucleophiles, different types of difunctionalized products were obtained in moderate
Reduction of Diesters of 1,2-Diols. Regioselective C−O Bond Cleavage of the Anionic Forms
作者:Norma A. Macías-Ruvalcaba、Cheryl L. Moy、Zi-Rong Zheng、Dennis H. Evans
DOI:10.1021/jo060535w
日期:2006.6.1
[GRAPHICS]The electrochemical reduction of benzoate diesters of glycols has been studied in acetonitrile and N, N-dimethylformamide as solvents. The reductions occur in two closely spaced one-electron steps, and it was found that the dianion diradicals decompose by one of two routes, depending on the substituents on the ethylene moiety: cleavage of two benzoates to produce alkene or formation of benzil by way of a postulated cyclic intermediate to produce also the dianion of the diol. These correspond to cleavage of the R-OC( O) Ar bonds and the RO-C( O) Ar bonds, respectively. When the radical formed by the former cleavage is a primary or secondary radical, the reaction is too slow to compete with the latter reaction that produces benzil. However, when that radical is either tertiary or benzylic, the former cleavage reaction is fast and no benzil is detected. The dianions of p-cyano-and p-nitrobenzoate esters are rather stable on the voltammetric time scale. However, the addition of lithium ions results in detectable formation of 4,4'-dicyanobenzil from four different p-cyanobenzoate diesters.
Anchisi, Carlo; Maccioni, Antonio; Maccioni, Anna Maria, Gazzetta Chimica Italiana, 1983, vol. 113, # 1/2, p. 73 - 76
作者:Anchisi, Carlo、Maccioni, Antonio、Maccioni, Anna Maria、Podda, Gianni
DOI:——
日期:——
New Metal Salt-Induced Homolytic Reactions. II. Modification of Free Radical Reactions by Copper Salts<sup>1</sup>
作者:M. S. KHARASCH、ANDREW FONO
DOI:10.1021/jo01087a007
日期:1959.5
25. Reactions of alkoxy-radicals. Part III. Formation of esters from alkyl nitrites