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A green and sustainable electrochemical hydroboration of carbonyl compounds with HBpin has been reported for the first time. Under catalyst-free and additive-free mild reaction conditions the corresponding boronic esters were obtained in excellent yields via the simple electrochemical hydroboration of various aldehydes and ketones with HBpin at room temperature. The scale-up reaction demonstrated potential practical applications. A plausible reaction mechanism was proposed based on the corresponding deuterium-labelling, radical inhibition and cyclic voltammetry experiments. [ABSTRACT FROM AUTHOR]

A low-valent magnesium(I) complex [(XylNacnac)Mg]2 was employed as a highly efficient precatalyst for the hydroboration of a variety of cyclic and linear organic carbonates, polycarbonates, CO2 and esters with HBpin under mild conditions. The resultant boronates can be used for the preparation of the corresponding value-added diols, triols or alcohols through hydrolysis. [ABSTRACT FROM AUTHOR]

The hydroboration of a wide range of ketones with pinacolborane can be achieved under catalyst-free and solvent-free conditions to provide the corresponding boronic esters in quantitative yields. A large gram-scale hydroboration of acetophenone with HBpin under the same conditions was also performed to afford the alcohol product in a high yield thus demonstrating the scalability of the newly developed simple protocol. [ABSTRACT FROM AUTHOR]

The well-defined lithium NCN-Pincer magnesiate complex [Li (THF) 4 ][NCN-MgBr 2 ] 2 based on a bis(imino)aryl ligand has been successfully prepared, crystallographic characterized and employed as an efficient catalyst for hydroboration of a wide range of aldehydes and ketones with pinacolborane (HBpin) at room temperature. Both aldehyde and ketone hydroboration proceeded efficiently (>99% conversion in <15 min) and could be directly carried out in a CDCl 3 solution. In addition, chemoselective hydroboration of aldehydes over ketones was also achieved under these conditions. [ABSTRACT FROM AUTHOR]

• A green electrochemical hydroboration of alkynes with HBpin was reported. • Various alkenyl boronic esters were obtained in good yields under catalyst-free conditions at room temperature. • A plausible reaction mechanism was proposed based on the corresponding experiments. A green and sustainable electrochemical hydroboration of various alkynes with HBpin has been reported for the first time. Under catalyst-free and additive-free mild reaction conditions the corresponding alkenyl boronic esters were obtained in good to excellent yields within 30 min at room temperature. A plausible reaction mechanism was proposed based on the corresponding experiments. [Display omitted] [ABSTRACT FROM AUTHOR]

Simple, commercially available Grignard reagents have been used as highly efficient precatalysts for the hydroboration of a wide range of aldehydes and ketones. The reaction employs very low catalyst loadings (aldehydes: 0.05 mol%, ketones: 0.5 mol%), and proceeds rapidly (aldehydes: 10 min, ketones: 20 min) under neat condition at room temperature. The Grignard reagent catalyst demonstrated good substrate scope, functional group tolerance, and high chemoselectivity in the carbonyl hydroboration. DFT calculations were performed to investigate the possible reaction mechanism. In contrast to the traditional stoichiometric use of Grignard reagents, this newly developed protocol provides a catalytic application of these reagents for molecular transformations. Image 1 • Grignard reagents have been employed as efficient precatalysts for various carbonyl hydroboration. • The Grignard reagent catalyst shows a high functional group tolerance and high chemoselectivity. • In contrast to the traditional stoichiometric use of Grignard reagents, this protocol provides a catalytic application. [ABSTRACT FROM AUTHOR]