Synthesis 2023; 55(14): 2166-2176
DOI: 10.1055/a-2050-3720
paper

Metal-Free Synthesis of Guanidines from Thioureas in Water Reactions Mediated by Visible Light

Rose Malina Annuur
a   Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
,
Trin Saetan
a   Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
,
Mongkol Sukwattanasinitt
a   Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
,
Sumrit Wacharasindhu
b   Green Chemistry for Fine Chemical Production and Environmental Remediation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
› Author Affiliations
This research was financially supported by the National Research Council of Thailand (NRCT) (NRCT5-RSA63001-16). R.M.A. was supported by an ASEAN and Non-ASEAN Countries Chulalongkorn University Scholarship.


Abstract

Metal-free synthesis of guanidines from thioureas under visible-light irradiation in water was successfully developed. Using 1–5 mol% of inexpensive and commercially available phenazine ethosulfate as a photocatalyst in the presence of 1 wt% cetyltrimethylammonium bromide (CTAB) as surfactant with K2CO3 as an additive base, transformations of a variety of thioureas into the corresponding guanidines under visible-light irradiation were achieved in moderate to high yields. The advantages of this reaction include the use of a metal-free photocatalyst, water as a nontoxic solvent, and ease of operating at room temperature in an open-flask manner.

Supporting Information



Publication History

Received: 02 December 2022

Accepted after revision: 08 March 2023

Accepted Manuscript online:
08 March 2023

Article published online:
13 April 2023

© 2023. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany