Aerobic α‐Sulfonylation of Ketones with Zinc Sulfinates in Aqueous Micellar Media: Highly Selective Access to β‐Keto Sulfones

Abstract

An efficient, inexpensive and environmentally friendly synthesis of β‐ketosulfones, via NaI‐catalyzed oxidative sulfonylation of ketones with zinc sulfinates, employing ethylene dibromide (EDB) and air as the oxidants, is described. EDB was shown to be a mild organic oxidant to convert NaI into molecular iodine that promote the cross‐coupling reactions of zinc sulfinates with ketones, producing β‐ketosulfones. Mechanistic studies indicated that a radical pathway might be involved in the reaction process. The key feature of the present protocol is the far greater solubility of NaI and sulfinates in micellar arrays present in aqueous solution where the oxidative coupling reactions are taking place.

Electrochemical Oxidation Involving Sulfonyl Hydrazine for the Synthesis of 2‐Sulfonyl Quinolines/Pyridines

“…To realize our idea and in order to optimize the reaction conditions, considering that the current [24][25][26] has a favorable effect on the formation and cleavage of CÀ S bond. [27,28] As shown in Table 1, we commenced our study using quinoline Noxide 1 a and p-toluenesulfonylhydrazide 2 a as a model reaction, n Bu 4 NPF 6 as an electrolyte and K 2 CO 3 as a base in cosolvent CH 3 CN/H 2 O, graphite rod as anode and platinum plate as cathode. To our delight, 2-Tosylquinoline 3 aa was obtained in 82 % yield with 15 mA constant current in an undivided cell (entry 1).…”