100% atom-economical and highly regio- and stereoselective iodosulfenylation of alkynes: a reagentless and sustainable approach to access (E)-β-iodoalkenyl sulfides and (Z)-tamoxifen. Issue 2 (16th January 2023)

• Record Type: Journal Article
• Authors: Satyanarayana, Appanapalli N. V.; Mukherjee, Nilanjana; Chatterjee, Tanmay
• Is Part Of: Green chemistry. Volume 25:Issue 2(2023)
• Page Start: 779
• Page End: 788
• Publication Date: 2023-01-16
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d2gc04101d
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : A 100% atom-economical iodosulfenylation of alkynes is developed using only iodine and disulfides via the in situ formation of the corresponding sulfenyl iodide intermediates to access ( E )-β-iodoalkenyl sulfides and ( Z )-tamoxifen. Abstract : Development of synthesis strategies with a green perspective to access stereodefined tetrasubstituted alkenes is challenging and thus highly desirable. Herein, we present a reagentless, 100% atom-economic, scalable and sustainable synthetic method for the highly regio- and stereoselective iodosulfenylation of alkynes using only iodine (0.5 equiv.) and disulfides (0.5 equiv.) to access important classes of stereodefined alkenes (tetrasubstituted or trisubstituted) i.e. ( E )-β-iodoalkenyl sulfides in moderate to excellent yields up to 96%. Significantly, the product, ( E )-(2-iodo-1, 2-diphenylvinyl)(phenyl)sulfane was synthetically diversified to various other potential classes of stereodefined tetrasubstituted alkenes including a marketed anti-breast cancer drug, ( Z )-tamoxifen. The notable advantages of this method over the previously developed ones for the iodosulfenylation of alkynes are (a) a reagentless, 100% atom-economic, cost-effective and sustainable protocol, (b) a straightforward scale-up process up to the multi-gram (10 g) scale without any compromise in the reaction outcome, (c) very clean reactions with most of the internal alkynes in accessing pure ( E )-β-iodoalkenyl sulfides without the requirement of huge organic solvent-consuming conventional purification techniques, i.e., work-up and column chromatography, (d) excellent green chemistry metrics such as 100% atom-economy, 96% atom-efficiency, 95.9% carbon-efficiency, 95.93% reaction-mass efficiency, low E -factor (0.19) and very high EcoScale score (84) and most importantly, (e) practical application of the protocol to a cost-effective and sustainable synthesis of ( Z )-tamoxifen.