L-Cysteine-Catalysed Hydration of Activated Alkynes

Hydration reactions consist of the introduction of a molecule of water into a chemical compound and are particularly useful to transform alkynes into carbonyls, which are strategic intermediates in the synthesis of a plethora of compounds. Herein we demonstrate that L-cysteine can catalyse the hydration of activated alkynes in a very effective and fully regioselective manner to access important building blocks in synthetic chemistry such as β-ketosulfones, amides and esters, in aqueous media. The mild reaction conditions facilitated the integration with enzyme catalysis to access chiral β-hydroxy sulfones from the corresponding alkynes in a one-pot cascade process in good yields and excellent enantiomeric ratios. These findings pave the way towards establishing a general method for metal-free, cost-effective, and more sustainable alkyne hydration processes.

Palladium-catalyzed preparation of Weinreb amides from boronic acids and N-methyl-N-methoxycarbamoyl chloride

A simple protocol for the synthesis of Weinreb benzamides and alpha,beta-unsaturated Weinreb amides through a palladium-catalyzed cross-coupling reaction between organoboronic acids and N-methoxy-N-methylcarbamoyl chloride has been developed. The method is also applicable to the use of potassium organotrifluoroborates.