The Synthesis and Base-Induced Breakdown of Triaryl 1,4-Oxathiins-An Experimental and DFT Study.

1,4-Oxathiins are valued for a breadth of bioactivities and are known commercial fungicides. This article explores a novel preparation of 2,3,6-trisubstituted 1,4-oxathiin-S,S-dioxides via the reaction of benzyl 1-alkynyl sulfones and aryl aldehydes under basic conditions. A total of 20 examples possessing exclusively a trans arrangement of the 2,3-diaryl substituents are exhibited; the products demonstrate a variation of functional groups on the aryl ring attached to the heterocyclic ring system.

Cope-Type Hydroamination of Vinylboronates.

Aminoboronic acid derivatives can serve as versatile synthetic intermediates and pharmacophores but remain difficult to synthesize. Herein we report a synthesis of the β-aminoboronic acid motif via anti-Markovnikov hydroamination of vinylboronates. This reaction benefits from the activating effect of the boronate substituent and forms novel BON-containing heterocycles, oxazaborolidine zwitterions.

A DFT examination of the role of proximal boron functionalities in the -alkylation of sulfenic acid anions.

Sulfenic acid anions represent an emerging nucleophile for the preparation of sulfoxides. Their S-functionalization chemistry can often be influenced by a nearby group that interacts with the component atoms of the sulfenate through non-bonding interactions. This study uses DFT methods to assess the importance of proximal boron-containing functional groups to direct -alkylation chemistry of selected sulfenate anions.