A sustainable process for catalytic oxidative bromination with molecular oxygen
Workin′ in a bromine: A palladium-polyoxometalate amphiphilic hybrid material serves as catalyst for oxidative brominations. The emulsion-based process avoids the use of toxic and corrosive bromination agents such as Br 2 or HBr, and uses molecular oxygen as oxidant. The only side product is water, which is also the reaction medium. The catalyst offers good recoverability and recyclability. Copyright
PHOTOCHEMICAL TRANSFORMATION OF TETRABROMOFURAN BY OXYGEN INTO 2,3,4,4-TETRABROMOBUT-2-EN-4-OLIDE IN THE SOLID STATE
The solid-state photo-oxidation (1) -> (2) recorded by Torrey in 1897 has been verified and structure (2) confirmed; a possible mechanism for the transformation involving free radicals is suggested.In contrast, the bromination (5) -> (2) reported by Hill and Cornelison in 1894 could not be repeated despite many attempts.An ionic mechanism for the preparation (4) -> (6) is proposed; the semi-aldehyde (6) in solution exists solely in the lactol form (7).