178626-04-5Relevant articles and documents
Base-Mediated Radical Borylation of Alkyl Sulfones
Huang, Mingming,Hu, Jiefeng,Krummenacher, Ivo,Friedrich, Alexandra,Braunschweig, Holger,Westcott, Stephen A.,Radius, Udo,Marder, Todd B.
, (2021/12/02)
A practical and direct method was developed for the production of versatile alkyl boronate esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B2neop2), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.
Vinyl Azides as Radical Acceptors in the Vitamin B12-Catalyzed Synthesis of Unsymmetrical Ketones
Dworakowski, Krzysztof R.,Pisarek, Sabina,Hassan, Sidra,Gryko, Dorota
supporting information, p. 9068 - 9072 (2021/11/30)
Vinyl azides are very reactive species and as such are useful building blocks, in particular, in the synthesis of N-heterocycles. They can also serve as precursors of ketones. These form in reactions of vinyl azides with nucleophiles or radicals. We have found, however, that under light irradiation vitamin B12 catalyzes the reaction of vinyl azides with electrophiles to afford unsymmetrical carbonyl compounds in decent yields. Mechanistic studies revealed that alkyl radicals are key intermediates in this transformation.
Cobalt(I)-Catalyzed Borylation of Unactivated Alkyl Bromides and Chlorides
Geetharani, K.,Prasad, K. Sujit,Varghese, Dominic,Verma, Piyush Kumar
, p. 1431 - 1436 (2020/03/13)
A cobalt-complex-catalyzed borylation of a wide range of alkyl halides with a diboron reagent (B2pin2 or B2neop2) has been developed under mild reaction conditions, demonstrating the first cobalt-mediated cross-coupling with alkyl electrophiles. This protocol allows alkyl boronic esters to be accessed from alkyl halides, including alkyl chlorides, which were used rarely as coupling partners. Mechanistic studies reveal the possible involvement of an alkyl radical intermediate in this cobalt-mediated catalytic cycle.