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Pnictogen-bonding catalysis: brevetoxin-type polyether cyclizations. | LitMetric

Pnictogen-bonding catalysis: brevetoxin-type polyether cyclizations.

Chem Sci

Department of Organic Chemistry , University of Geneva, Geneva , Switzerland . Email: ; http://www.unige.ch/sciences/chiorg/matile/ ; Tel: +41 22 379 6523.

Published: July 2020

AI Article Synopsis

Article Abstract

Pnictogen-bond donors are attractive for use in catalysis because of deep σ holes, high multivalency, rich hypervalency, and chiral binding pockets. We here report natural product inspired epoxide-opening polyether cyclizations catalyzed by fluoroarylated Sb(v) > Sb(iii) > Bi > Sn > Ge. The distinctive characteristic found for pnictogen-bonding catalysis is the breaking of the Baldwin rules, that is selective cyclization into the -fused ladder oligomers known from the brevetoxins. Moreover, tris(3,4,5-trifluorophenyl)stibines and their hypervalent stiborane catecholates afford different -Baldwin stereoselectivity. Lewis (SbCl), Brønsted (AcOH) and π acids fail to provide similar access to these forbidden rings. Like hydrogen-bonding catalysis differs from Brønsted acid catalysis, pnictogen-bonding catalysis thus emerges as the supramolecular counterpart of covalent Lewis acid catalysis.

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Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690316PMC
http://dx.doi.org/10.1039/d0sc02551hDOI Listing

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