Synthesis 2024; 56(07): 1183-1199
DOI: 10.1055/a-2193-4615
paper
Emerging Trends in Glycoscience

Activation of Stable and Recyclable Phenylpropiolate Glycoside (PPG) Donors by Iron Catalysis

Anjali Aghi
,
Saksham Mishra
,
Amit Kumar
This work is supported by the Science and Engineering Research Board (SERB), New Delhi (grant no CRG/2019/000452) and the Indian Institute of Technology (IIT), Patna. A. Aghi thanks SERB New Delhi for a research fellowship and S. Mishra thanks IIT Patna for a research fellowship.


Abstract

The glycosylation reaction is one of the important aspects of carbohydrate chemistry, where two different units are frequently linked through C–O bonds. In the pursuit of advancing this field, the design and development of sustainable catalytic methods for O-glycosylation, which can provide an alternate and effective tool to traditional protocols involving stoichiometric promoters and classical donors, are considered as highly challenging, yet important facets of glycochemistry. Herein, we report a simple and efficient Fe(III)-catalyzed method for O-glycosylation through the activation of bifunctional phenylpropiolate glycoside (PPG) donors. This mild and effective method involves the use of the inexpensive and less toxic FeCl3 as catalyst and easily synthesizable, benchtop-stable glycosyl ester-based PPG donors, which react with various sugar as well as non-sugar-based acceptors to deliver the corresponding O-glycosides in good yields with moderate anomeric selectivity, along with regeneration of easily separable phenylpropiolic acid. Importantly, d-mannose and l-rhamnose-based PPG donors afforded the corresponding O-glycosides in high α-anomeric selectivity. The reaction conditions were further explored for the synthesis of trisaccharides.

Supporting Information



Publication History

Received: 26 July 2023

Accepted after revision: 17 October 2023

Accepted Manuscript online:
17 October 2023

Article published online:
20 November 2023

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