Dioxygen concentration-dependent selective hydroxysulfonylation of olefins by rose bengal-sensitized photocatalysis.

The synthesis of β-hydroxysulfones selectively in preference to β-ketosulfones by dye-sensitized photocatalysis is demonstrated by employing inexpensive and readily available olefins and sulfonyl hydrazides/-hydroxy sulfonamides in the presence of oxygen. The facile hydroxysulfonylation reaction, which involves the use of rose bengal (RB) as a photocatalyst and dioxygen as an oxidant, permits access selectively to secondary and tertiary β-hydroxysulfones in good to excellent isolated yields at rt and is compatible with aryl, heteroaryl and alkyl sulfonyl hydrazides. Mechanistically, sulfonyl radicals are generated by a cascade of redox reactions, set off by the photocatalyst RB, between sulfonyl hydrazide and dioxygen.

Oxidation of Thiols with IBX or DMP: One-Pot Access to Thiosulfonates or 2-Iodobenzoates and Applications in Functional Group Transformations.

-Iodoxybenzoic acid (IBX) and Dess-Martin periodinane (DMP) are employed for thiol to thiosulfonate conversion at rt. DMP is better than IBX in terms of reaction rate, conversion, and required equivalents. IBX-mediated oxidation of benzyl thiols produced thiosulfonates, whereas DMP afforded -benzyl esters.

Acid-Functionalised Magnetic Ionic Liquid [AcMIm]FeCl as Catalyst for Oxidative Hydroxylation of Arylboronic Acids and Regioselective Friedel-Crafts Acylation.

An acid-functionalised, magnetic, room-temperature ionic liquid, 1-acyl-3-methylimidazolium tetrachloroferrate ([AcMIm]FeCl ), was synthesised and its optical, magnetic, and thermal properties were investigated. The magnetic moment (0.05402 emu in 2 T magnetic fields) showed strong paramagnetic behaviour, and thermogravimetric analysis indicated very good thermal stability with a decomposition temperature higher than 230 °C.