Issue 27, 2020

Pnictogen-bonding catalysis: brevetoxin-type polyether cyclizations


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 endo cyclization into the trans-fused ladder oligomers known from the brevetoxins. Moreover, tris(3,4,5-trifluorophenyl)stibines and their hypervalent stiborane catecholates afford different anti-Baldwin stereoselectivity. Lewis (SbCl3), 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.

Graphical abstract: Pnictogen-bonding catalysis: brevetoxin-type polyether cyclizations

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Article information

Article type
Edge Article
05 May 2020
17 Jun 2020
First published
25 Jun 2020
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2020,11, 7086-7091

Pnictogen-bonding catalysis: brevetoxin-type polyether cyclizations

A. Gini, M. Paraja, B. Galmés, C. Besnard, A. I. Poblador-Bahamonde, N. Sakai, A. Frontera and S. Matile, Chem. Sci., 2020, 11, 7086 DOI: 10.1039/D0SC02551H

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