Acid-catalyzed isomerization of 3-indolyl sulfides to 2-indolyl sulfides: first synthesis of 3-unsubstituted 2-arylthioindoles. Evidence for a complex intermolecular process
摘要:
The acid-catalyzed isomerization of 3-indolyl sulfides 1 to the corresponding 2-indolyl sulfides 4 provides the first synthesis of 3-unsubstituted 2-(arylthio)indoles, a hitherto unattainable class of compounds. When catalyzed by trifluoroacetic acid, the isomerization proceeds mainly via an intermolecular mechanism involving initial disproportionation to a 2,3-indolyl bis-sulfide 5 and an unsubstituted counterpart 6 followed by further interaction of these species to yield the rearranged isomer 4. A mechanism is proposed involving a role for the acid in the sulfenyl-transfer steps. This type of process also occurs, to a lesser extent, in the polyphosphoric acid catalyzed isomerization.
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.
Iodine-Catalyzed Mono- and Disulfenylation of Indoles in PEG<sub>400</sub>
through a Facile Microwave-Assisted Process
作者:Rajjakfur Rahaman、Pranjit Barman
DOI:10.1002/ejoc.201701293
日期:2017.11.16
An iodine-catalyzed versatile green method for the synthesis of mono- and 2,3-bis-sulfenyl indoles has been presented. Various indoles can react with alkyl or aryl sodiumsulfinates using hydrogen peroxide as an oxidizing agent in PEG400 under microwave conditions. This simple method enabled the rapid synthesis of mono- and 2,3-bis-sulfenylindoles with good to excellent yields under metal free conditions
the direct synthesis of 3-sulfanylindoles from indoles and thiols under an atmospheric pressure of molecular oxygen as a reoxidant. For example, the reaction of 2-phenylindole with benzenethiol in the presence of a catalytic amount of VO(acac)2, potassium iodide, and 2,6-di-tert-butyl-p-cresol in chlorobenzene under molecular oxygen proceeds to afford 2-phenyl-3-(phenylsulfanyl)indole in 86% yield
Electrochemical Thiolation and Borylation of Arylazo Sulfones with Thiols and B
<sub>2</sub>
pin
<sub>2</sub>
作者:Rongkang Wang、Fangming Chen、Lvqi Jiang、Wenbin Yi
DOI:10.1002/adsc.202001518
日期:2021.3.29
arylazo sulfones were used as radical precursors for carbon‐heteroatom bond formation under electrochemical conditions. Moreover, the scalability of this approach was evaluated by performing the electrochemical thiolation and borylation of arylazo sulfones with thiols and B2pin2 on a gram scale. This protocol not only avoided the use of stoichiometric oxidants, metal catalysts, activating agents and