Diboron reagents in the deoxygenation of nitrones.

Bnep efficiently promotes the N-O cleavage of nitrones to form imines in very high yields a simple, efficient, sustainable, functional group tolerant and scalable protocol. The reaction occurs in the absence of additives through a concerted mechanism. We demonstrated that DMPO and TEMPO, typically used as radical traps, are also deoxygenated by diboron reagents, which demonstrates their limitation as mechanistic probes.

Coupling of thiols and aromatic halides promoted by diboron derived super electron donors.

We have proven that pyridine-boryl complexes can be used as superelectron donors to promote the coupling of thiols and aromatic halides through a S1 mechanism. The reaction is efficient for a broad substrate scope, tolerating heterocycles including pyridines, enolizable or reducible functional groups. The method has been applied to intermediates in drug synthesis as well as interesting functionalized polythioethers through a controlled and consecutive intramolecular electron transfer process.

p Modulation of Pyrrolidine-Based Catalytic Polymers Used for the Preparation of Glycosyl Hydrazides at Physiological pH and Temperature.

Inspired by the ability of enzymes to use the surrounding hydrophobic and/or polarizable groups to modulate the p of a given amino acid, we designed a series of soluble polymers able to decrease the basicity of pyrrolidine (from 11.2 to 8.6 p units), which clearly increases its aminocatalytic activity at physiological pH in C═N bond formation reactions via ion iminium activation.