Umpolung Difunctionalization of Carbonyls via Visible-Light Photoredox Catalytic Radical-Carbanion Relay
作者:Shun Wang、Bei-Yi Cheng、Matea Sršen、Burkhard König
DOI:10.1021/jacs.0c00629
日期:2020.4.22
catalysis with the Wolff–Kishner (WK) reaction allows the difunctionalization of carbonyl groups by a radical-carbanion relay sequence (photo-Wolff–Kishner reaction). Photoredox initiated radical addition to N-sulfonylhydrazones yields α-functionalized carbanions following the WK-type mechanism. With sulfur-centered radicals, the carbanions are further functionalized by reaction with electrophiles
Copper-Catalyzed Direct Ortho-Alkylation of <i>N</i>-Iminopyridinium Ylides with <i>N</i>-Tosylhydrazones
作者:Qing Xiao、Lin Ling、Fei Ye、Renchang Tan、Leiming Tian、Yan Zhang、Yuxue Li、Jianbo Wang
DOI:10.1021/jo4002883
日期:2013.4.19
Copper-catalyzedcross-coupling of N-tosylhydrazones with N-iminopyridinium ylides leads to the direct C–H alkylation. This direct C–H bond alkylation transformation uses inexpensive CuI as the catalyst without any ligand. The reaction is operationally simple and conducted under mild conditions, giving the corresponding alkylated pyridines in moderate to good yields. DFT calculation provides insights
Straightforward Reductive Esterification of Carbonyl Compounds with Carboxylic Acids through Tosylhydrazone Intermediates
作者:Angel-Humberto García-Muñoz、María Tomás-Gamasa、M. Carmen Pérez-Aguilar、Erick Cuevas-Yañez、Carlos Valdés
DOI:10.1002/ejoc.201200647
日期:2012.7
The reaction of carboxylicacids with tosylhydrazones in basic media gives rise to the corresponding esters through an O–H insertion reaction in the in situ generated diazo compound. The process is operationally very simple, catalyst free, and very general with regard to the structure of both coupling partners. In particular, the esterification can be accomplished by employing tosylhydrazones derived
Unsymmetrical 1,1-diborated multisubstituted sp<sup>3</sup>-carbons formed via a metal-free concerted-asynchronous mechanism
作者:Ana B. Cuenca、Jessica Cid、Diego García-López、Jorge J. Carbó、Elena Fernández
DOI:10.1039/c5ob01523e
日期:——
unsymmetrical 1,1-diboration of diazo compounds, formed in situ from aldehydes and cyclic and non-cyclic ketones, in the absence of any transition metal complex. The heterolytic cleavage of the mixed diboron reagent, Bpin–Bdan, and the formation of two geminal C–Bpin and C–Bdan bonds has been rationalised based on DFT calculations to occur via a concerted-asynchronous mechanism. Diastereoselection is attained
The Pd‐catalyzed reaction between 2,2′‐dibromobiphenyls and related systems with tosylhydrazones gives rise to new π‐extendedconjugatedpolycarbo‐ and heterocyclesthrough an autotandem process involving a cross‐coupling reaction followed by an intramolecular Heck cyclization. The reaction shows wide scope regarding both coupling partners. Cyclic and acyclic tosylhydrazones can participate in the