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
Construction of NH‐Unprotected Spiropyrrolidines and Spiroisoindolines by [4+1] Cyclizations of γ‐Azidoboronic Acids with Cyclic
<i>N</i>
‐Sulfonylhydrazones
作者:Lucía López、María‐Paz Cabal、Carlos Valdés
DOI:10.1002/anie.202113370
日期:2022.1.10
N-sulfonylhydrazones of cyclic ketones are readily transformed into NH-free spirocyclic pyrrolidines and isoindolines by reaction with γ-azidoboronic acids. The transition-metal-free transformation is widely applicable and represents a new disconnection towards spirocyclic pyrrolidines. The application of the reaction in the modification of natural steroids and other biorelevant molecules highlights