Synlett 2021; 32(03): 229-234
DOI: 10.1055/s-0040-1707296
synpacts

Chiral Auxiliaries for Stereoselective Electrophilic Aromatic Substitutions

Mona Sharafi
,
Joseph P. Campbell
,
Kyle E. Murphy
,
Reilly Osadchey Brown
,
Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT 05405, USA   Email: Severin.schneebeli@uvm.edu
› Author Affiliations
This research was supported by a National Science Foundation (NSF) grant from the Chemistry Division (grant number: CHE-1848444) awarded to S.T.S. R.O.B. was supported by a Summer Undergraduate Research Fellowship at the University of Vermont. Computational resources for this paper were provided by the Vermont Advanced Computing Core (VACC).


Abstract

Electrophilic aromatic substitution reactions are of profound importance for the synthesis of biologically active compounds and other advanced materials. They represent an important means to activate specific aromatic C–H bonds without requiring transition-metal catalysts. Surprisingly, few stereoselective variants are known for electrophilic aromatic substitutions, which limits the utility of these classical reactions for stereoselective synthesis. While many electrophilic aromatic substitutions lead to achiral products (due to the planar nature of aromatic rings), there are important examples where chiral products are produced, including desymmetrization reactions of aromatic cyclophanes and of prochiral substrates with multiple aromatic rings. This Synpacts article now illustrates how chiral arms, when placed precisely above and underneath delocalized carbocations, can act as chiral auxiliaries to convert classical electrophilic aromatic substitution reactions into powerful diastereo- and enantioselective transformations.



Publication History

Received: 17 July 2020

Accepted after revision: 28 August 2020

Article published online:
12 November 2020

© 2020. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany