Xia M, Lambu MR, Tatina MB, Judeh ZMA. A Practical Synthesis of Densely Functionalized Pyrroles via a Three-Component Cascade Reaction between Carbohydrates, Oxoacetonitriles, and Ammonium Acetate.
J Org Chem 2020;
86:837-849. [PMID:
33326248 DOI:
10.1021/acs.joc.0c02381]
[Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A practical three-component reaction between unactivated carbohydrates, oxoacetonitriles, and ammonium acetate gave densely functionalized pyrroles in 75-96% yields. Disaccharides afforded novel pyrrolo-glycosides. This metal-free, Et3N-catalyzed cascade reaction proceeded with exclusive chemo-, regio-, and stereoselectivities and showed a wide substrate scope with high atom economy. It also proceeded successfully at a 2 g scale, demonstrating potential for large-scale synthesis. The functional groups on the pyrroles permit easy transformation to other handles for the construction of more complex structures. The reaction proceeded through a cascade mechanism involving several intermediates identified by mass spectrometric analysis. This work has great potential for the sustainable production of densely functionalized pyrroles from cheap and widely available carbohydrates and represents a key advancement in the sustainable synthesis of these ubiquitous heterocycles.
Collapse