RESUMEN
A method for amide-directed Ni-catalyzed diastereoselective arylboration of cyclopentenes is disclosed. The reaction allows for the synthesis of sterically congested cyclopentane scaffolds that contain an easily derivatized boronic ester and amide functional handles. The nature of the amide directing group and its influence on the reaction outcome are investigated and ultimately reflect a predictably selective reaction based on the solvent and base counterion.
Asunto(s)
Boro/química , Ciclopentanos/química , Amidas/química , Ésteres , Estructura Molecular , Níquel/química , EstereoisomerismoRESUMEN
Metal heteroanionic materials, such as oxyhalides, are promising photocatalysts in which band positions can be engineered for visible-light absorption by changing the halide identity. Advancing the synthesis of these materials, bismuth oxyhalides of the form BiOX (X = Cl, Br) have been prepared using rapid and scalable ultrasonic spray synthesis (USS). Central to this advance was the identification of small organohalide molecules as halide sources. When these precursors are spatially and temporally confined in the aerosol phase with molten salt fluxes, powders composed of single-crystalline BiOX nanoplates can be produced continuously. A mechanism highlighting the in situ generation of halide ions is proposed. These materials can be used as photocatalysts and provide proof-of-concept toward USS as a route to more complex bismuth oxyhalide materials.
RESUMEN
A method for the Ni-catalyzed arylboration of unactivated monosubstituted, 1,1-disubstituted, and trisubstituted alkenes is disclosed. The reaction is notable in that it converts highly substituted alkenes, aryl bromides, and diboron reagents to products that contain a quaternary carbon and a synthetically versatile carbon-boron bond with control of stereoselectivity and regioselectivity. In addition, the method is demonstrated to be useful for the synthesis of saturated nitrogen heterocycles, which are important motifs in pharmaceutical compounds. Finally, due to the unusual reactivity demonstrated, the mechanistic details of the reaction were studied with both computational and experimental techniques.