Roberta A. Oliveira

Differentiation and assignment of vinyl telluride regioisomers by 1H-125Te gHMBC

Complete 1H, 13C, and 125Te NMR spectral data for some vinyl tellurides are described. The 1H–125Te gHMBC experiment was used for the complete chemical shift assignment and structure elucidation of a mixture of regioisomers. The assignment (125Te NMR) and coupling constants (JH,H) for all regioisomers are described for the first time. Copyright

Allylation of Functionalized Aldehydes by Potassium Allyltrifluoroborate Catalyzed by 18-Crown-6 in Aqueous Media

An efficient method for the allylation of aldehydes containing a broad range of functional groups using potassium allyltrifluoroborate is described. The reaction utilizes a catalytic amount of 18-C-6 in biphasic media under open atmosphere and room temperature to provide the corresponding homoallylic alcohols in high yields and without the necessity of any subsequent purification.

Metal free synthesis of homoallylic alcohols promoted by ultrasound

The use of ultrasound irradiation to promote the allylation of aldehydes containing different functionalities with potassium allyltrifluoroborates is described. The method features the use of a minimum amount of acetone as solvent, without any other catalyst or promoter. The products were obtained in high yields, short reaction times, at room temperature and without the need of further purification.

An Efficient Method for the Hydrolysis of Potassium Organotrifluoroborates Promoted by Montmorillonite K10

An efficient and non-expensive method for conversion of diverse potassium organotrifluoroborates to their corresponding boronic acids promoted by montmorillonite K10 using water as the reaction solvent is described. Further interconversion of potassium organotrifluoroborates to their corresponding boronic esters, via boronic acid intermediates was also successfully accomplished. The products were obtained in good yields, being the rate of hydrolysis influenced by the type of substituent present in the boronic acid.