A novel intramolecular cyclization of isothiocyanyl amino acids/peptide is reported to arrive at unnatural thioxoimidazolidinyl (TOI)/thioxooxazolidinyl (TOO) amino acids for the first time. Interestingly, analogous isothiocyanyl amines under a similar reaction condition either follow 5-endo-dig cyclization to offer 5-membered thiourea or acyclic diethylaminyl thiourea derivative instead of 6-membered cyclic thiourea.
Bibliographical noteFunding Information:
The authors thank the Department of Science and Technology (DST-SR/SI/OC-69/2008), Department of Biotechnology (DBT: BT/PR16620/NER/95/223/2015), and COE-FAST scheme [5-5/2014-TS.VII], MHRD, New Delhi, Govt. of India for generous funding.
© 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.
- 5-endo-dig cyclization
- 5-membered thiourea
- Intramolecular cyclization of isothiocyanyl amino acids/peptide
- Isothiocyanyl amines
- Unnatural thioxoimidazolidinyl (TOI)/thioxooxazolidinyl (TOO) amino acids