Synthesis of 1,2,5-oxathiazole-S-oxides by 1,3 dipolar cycloadditions of nitrile oxides to α-oxo sulfines

McCaw, Patrick G.; Khandavilli, Udaya Bhaskara Rao; Lawrence, Simon E.; Maguire, Anita R.; Collins, Stuart G.

Synthesis of 1,2,5-oxathiazole-S-oxides by 1,3 dipolar cycloadditions of nitrile oxides to α-oxo sulfines

Files

OBC_Carbene_Paper_CORA.pdf(606.26 KB)

Accepted Version

c8ob02691b1.pdf(2.58 MB)

Supplementary Information

c8ob02691b2.cif(2.34 MB)

Crystal Structure Data

Date

2018-12-12

Authors

McCaw, Patrick G.

Khandavilli, Udaya Bhaskara Rao

Lawrence, Simon E.

Maguire, Anita R.

Collins, Stuart G.

Publisher

Royal Society of Chemistry

Published Version

10.1039/C8OB02691B

Abstract

Synthetic methodology for the generation of novel 1,2,5-oxathiazole-S-oxides from cycloaddition of nitrile oxide dipoles with α-oxo sulfines generated in situ via the α-sulfinyl carbenes derived from α-diazosulfoxides is described. Experimental evidence and mechanistic rationale for the unanticipated interconversion of the diastereomeric 1,2,5-oxathiazole-S-oxide cycloadducts are discussed. Notably, using rhodium acetate as a catalyst at 0 °C under traditional batch conditions led to the selective formation and isolation of the kinetic isomers, while, in contrast, using continuous flow thermolysis, optimal conditions for the synthesis and isolation of the thermodynamic isomers were established.

Keywords

Rhodium acetate , Catalyst , Kinetic isomers , Continuous flow thermolysis , Thermodynamic isomers

Citation

McCaw, P. G., Khandavilli, U. B. R., Lawrence, S. E., Maguire, A. R. and Collins, S. G. (2018) 'Synthesis of 1,2,5-oxathiazole-S-oxides by 1,3 dipolar cycloadditions of nitrile oxides to α-oxo sulfines', Organic and Biomolecular Chemistry, 17(3), pp. 622-638. doi:10.1039/C8OB02691B