Synthesis 2017; 49(06): 1319-1326
DOI: 10.1055/s-0036-1588102
paper
© Georg Thieme Verlag Stuttgart · New York

Catalytic Alkylation of 2-Aryl-2-oxazoline-4-carboxylic Acid Esters Using Cyclopeptoids; Newly Designed Phase-Transfer Catalysts

Rosaria Schettini
Dipartimento di Chimica e Biologia ‘A. Zambelli’, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy   Email: iizzo@unisa.it   Email: gdsala@unisa.it
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Assunta D’Amato
Dipartimento di Chimica e Biologia ‘A. Zambelli’, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy   Email: iizzo@unisa.it   Email: gdsala@unisa.it
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Francesco De Riccardis
Dipartimento di Chimica e Biologia ‘A. Zambelli’, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy   Email: iizzo@unisa.it   Email: gdsala@unisa.it
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Giorgio Della Sala*
Dipartimento di Chimica e Biologia ‘A. Zambelli’, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy   Email: iizzo@unisa.it   Email: gdsala@unisa.it
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Irene Izzo*
Dipartimento di Chimica e Biologia ‘A. Zambelli’, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy   Email: iizzo@unisa.it   Email: gdsala@unisa.it
› Author Affiliations
Further Information

Publication History

Received: 13 September 2016

Accepted after revision: 27 October 2016

Publication Date:
24 November 2016 (online)


Abstract

Nonionic, chiral macrocyclic peptoids are efficient phase-transfer catalysts in the C-4 enantioselective alkylation of 2-[4-(trifluoromethyl)phenyl]-2-oxazoline-4-carboxylic acid esters. Screening of the structural features of cyclic peptoids, namely the ring size, symmetry elements­, number of proline residues, and substituents on the side chains, showed that the alternated N-(4-methoxybenzyl)glycine/l-proline cyclohexapeptoid is the optimal catalyst (good yields and up to 75% ee) for the stereocontrolled construction of α-alkylated serine tert-butyl esters.

Supporting Information