Hypervalent iodine(III)-mediated regioselective N-acylation of 1,3-disubstituted thioureas.
Reaction of asymmetrical 1,3-disubstituted thioureas with diacetoxyiodobenzene (DIB) produces regioselectively N-acetylurea in shorter time. Regioselectivity is dependent on the pKa's of the amine attached to the thiourea moiety with acylation taking place toward the amine having a lower pKa. This is the first example of DIB being employed as an N-acetylating agent. A mechanism for this novel transformation is also proposed. Mild reaction conditions, shorter reaction times, high efficiencies, environmentally benign methods, and facile isolation of the desired product make the present methodology a most suitable alternative.
Singh
C B
CB
Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India.
Ghosh
Harisadhan
H
Murru
Siva
S
Patel
Bhisma K
BK
D000215:Acylation; D007462:Iodobenzenes / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D013890:Thiourea / Q000031:analogs & derivatives / Q000737:chemistry*; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
D007462:Iodobenzenes; D014508:Urea; D013890:Thiourea