Manganese catalysed sulfenylation of N-methyl amides with arenesulfonyl hydrazides

Abstract

A convenient oxidative sulfenylation method for the formation of various sulfenyl amides has been reported. Arenesulfonyl hydrazine as a sulfur source in the presence of a manganese salt can activate the sp(3) C-H bond of N-methyl amides through a free-radical pathway using di-tert-butyl peroxide (DTBP).

Sulfonyl Hydrazides in Organic Synthesis: A Review of Recent Studies

“…Herein, we will introduce several metal‐catalyzed sulfenylation, where [RS . ] species were generated by decomposition of thiodiazonium intermediates (Eq.…”

CeCl3⋅7H2O‐NaI Promoted Regioselective Sulfenylation of Indoles with Sulfonylhydrazides

“…On the other hand displacement of molecular nitrogen from G gives the sulfenyl iodide H , which is attacked by indole 6 to give the required product 3‐aryl sulfenyl indole derivatives I . A similar mechanism for sulfenylation of N ‐methyl amides with arene sulfoylhydrazides has been proposed using Mn(II)acetate …”

“…Interestingly, the reaction of 5-bromoindole with substituted hydrazides such as benzenesulfonylhydrazide, p-toluenesulfonylhydrazide, p-methoxybenzenesulfonyl hydra- zide, methylsulfonylhydrazide and mesitylsulfonylhydrazide afforded the corresponding 3-arylthioindole derivatives in excellent yields (Scheme 1, entries 6,7,10,12,17,24). Indoles containg elecrtron donating groups were smoothly converted to 3-arylthioindoles (Scheme 1, entries 4,5,9,13,19,23). Indoles containg electron withdrawing groups such as 5-nitro and 4-cyano were less reactive compared to indoles containing elecrtron donating groups & we observed 30 %conversion only, the remaining starting material was recovered back (Scheme 1, entries 20,21,22,25).…”

“…A similar mechanism for sulfenylation of N-methyl amides with arene sulfoylhydrazides has been proposed using Mn(II)acetate. [19]…”

Regioselective Mono‐ and Bis‐Sulfenylation of Active Methylene Compounds

“…A few reports of particular interest on mono-sulfenylation deal with the sulfenylation and dehydrosulfenylation of amides, [24] the sulfenylation of esters and ketones, [25] rhodiumcatalysed thiolation of 1-nitroalkanes [26] and the synthesis of thioethers by use of carbon tetrachloride as a mild oxidant. [27] The asymmetric sulfenylation of -keto esters [28] would be expected to provide versatile building templates and synthons for biologically active molecules, [29] which is also in the purview of mono-sulfenylation.…”