Synthesis 2018; 50(24): 4777-4795
DOI: 10.1055/s-0037-1610311
short review
© Georg Thieme Verlag Stuttgart · New York

Macrocyclic Hosts in Asymmetric Phase-Transfer Catalyzed Reactions

,
Marina Sicignano
,
,
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Dipartimento di Chimica e Biologia ‘A. Zambelli’, Università degli Studi di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy   Email: gdsala@unisa.it
› Author Affiliations
The University of Salerno is gratefully acknowledged for funding (FARB).
Further Information

Publication History

Received: 27 August 2018

Accepted after revision: 28 September 2018

Publication Date:
22 October 2018 (online)


Abstract

The introduction and development of neutral macrocyclic hosts capable of complexing ions within their pre-organized cavity, has been of utmost importance in supramolecular chemistry. Their ability to form stable organic-soluble metal–macrocycle complexes opened up the way to their application in phase-transfer catalysis (PTC) as a viable alternative to quaternary onium salts. In particular, their conformationally rigid preorganized backbone, accommodating organic substrates in defined orientations, promotes highly efficient stereoselective reactions. This short review summarizes the applications of neutral macrocyclic hosts in stereoselective PTC, highlighting the difference and possible complementarity with quaternary ammonium salts.

1 Introduction

2 Crown Ethers and Related Coronands

2.1 Enantioselective PTC with Chiral Macrocyclic Coronands

2.2 Enantioselective PTC Reactions Catalyzed by Chiral Quaternary Ammonium Salts with Achiral Crown Ether Co-catalysts

3 Cyclic Peptoids

4 Miscellaneous Chiral Macrocyclic Hosts

5 Summary and Outlook