Nitrosonium ion catalysis: aerobic, metal-free cross-dehydrogenative carbon–heteroatom bond formation
作者:Luis Bering、Laura D’Ottavio、Giedre Sirvinskaite、Andrey P. Antonchick
DOI:10.1039/c8cc08328b
日期:——
coupling of heteroarenes with thiophenols and phenothiazines has been developed under mild and environmentally benign reaction conditions. For the first time, NOx+ was applied for catalytic C–S and C–N bond formation. A comprehensive scope for the C–H/S–H and C–H/N–H cross-dehydrogenative coupling was demonstrated with >60 examples. The sustainable cross-coupling conditions utilize ambient oxygen as the
杂芳烃与硫酚和吩噻嗪的催化交叉脱氢偶联已在温和且环境友好的反应条件下得到发展。首次将NO x +用于催化C–S和C–N键的形成。用60多个例子证明了C–H / S–H和C–H / N–H交叉脱氢偶联的综合范围。可持续的交叉偶联条件利用环境氧作为末端氧化剂,而水是唯一的副产物。
Cooperative catalysis by bovine serum albumin–iodine towards cascade oxidative coupling-C(sp<sup>2</sup>)–H sulfenylation of indoles/hydroxyaryls with thiophenols on water
作者:Saima Saima、Danish Equbal、Aditya G. Lavekar、Arun K. Sinha
DOI:10.1039/c6ob00930a
日期:——
economically reliable. Further, the gram scale synthesis of a COX-2 inhibitor (3-(pyridin-2-ylthio)-1H-indole), regioselectivity and recyclability (up to four cycles) are the additional merits of this cooperative cascade bio-chemocatalytic (BSA–I2) protocol. Moreover, HPLC and ESI-MS provide powerful insights into the mechanistic aspects of the above cascade sulfenylation reaction.
A metal‐free aerobicoxidative C–H sulfenylation of aryl‐fused cyclic amines with various thiols was developed with excellent functional compatibility. While flavin I catalyzed the C–H sulfenylation of indolines to afford 3‐sulfenylindoles, flavin II enabled transformations resulting in substitution at the position para to the N atom on the aryl ring to obtain 6‐sulfenylquinolines.
An iodine-catalyzed regioselective sulfenylation of indoles in the presence of DMSO has been presented. Various indoles can react with aryl thiols or alkyl thiols to afford their corresponding 3-sulfenylindoles in good to excellent yields. The notable features of this protocol include easy operation, metal-free reaction conditions, and excellent functional group tolerance.
The C-3 sulfenylation reaction of indoles has been achieved under mild reaction conditions by simply employing NaOH as promoter and thiols as thiolating reagents. This simple method allows for easy and rapid synthesis of various 3-sulfenylated indoles with generally good to excellent yields. Primary attempts in scale-up synthesis give satisfactory result.