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4659556 
Journal Article 
Thiol-ene "click" reaction triggered by neutral ionic liquid: the "ambiphilic" character of [hmim]Br in the regioselective nucleophilic hydrothiolation 
Kumar, R; Saima, R; Shard, A; Andhare, NH; Richa, NH; Sinha, AK 
2015 
Yes 
Angewandte Chemie (International Edition)
ISSN: 1433-7851
EISSN: 1521-3773 
Wiley-VCH Verlag 
54 
3 
828-832 
English 
25430704 
WOS:000348372200013 
Thiol-ene "click" chemistry has emerged as a powerful strategy to construct carbon-heteroatom (C-S) bonds, which generally results in the formation of two regioisomers. To this end, the neutral ionic liquid [hmim]Br has been explored as a solvent cum catalyst for the synthesis of linear thioethers from activated and inactivated styrene derivatives or secondary benzyl alcohols and thiols without the requirement of using a metal complex, base, or free radical initiator. Furthermore, detailed mechanistic investigations using (1)H NMR spectroscopy and quadrupole time-of-flight electrospray ionization mass spectrometry (Q-TOF ESI-MS) revealed that the "ambiphilic" character of the ionic liquid promotes the nucleophilic addition of thiol to styrene through an anti-Markovnikov pathway. The catalyst recyclability and the extension of the methodology for thiol-yne click chemistry are additional benefits. A competitive study among thiophenol, styrene, and phenyl acetylene revealed that the rate of reaction is in the order of thiol-yne>thiol-ene>dimerization of thiol in [hmim]Br. 
Ambiphiles; Click chemistry; Ionic liquids; Mass spectrometry; NMR spectroscopy