Helical Polycarbenes Bearing <i>D</i>-Prolinol Ester Pendants: An Efficient Catalyst for Asymmetric Michael Addition Reaction

Na Liu; Xinyue Zhou; Li Zhou; Zongquan Wu

doi:10.3390/catal11111369

Catalysts (Nov 2021)

Helical Polycarbenes Bearing <i>D</i>-Prolinol Ester Pendants: An Efficient Catalyst for Asymmetric Michael Addition Reaction

Na Liu,
Xinyue Zhou,
Li Zhou,
Zongquan Wu

Affiliations

Na Liu: Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China
Xinyue Zhou: Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China
Li Zhou: Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China
Zongquan Wu: Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China

DOI: https://doi.org/10.3390/catal11111369
Journal volume & issue: Vol. 11, no. 11
p. 1369

Abstract

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A novel diazoacetate monomer (1) carrying tert-butyloxycarboryl (Boc) protected D-prolinol ester was designed and synthesized successfully. Molecular weight-controlled polymerization of 1 using the complex of π-allylPdCl coordinated Wei-phos (LR) ligand gives a series of helical polycarbenes (poly-1ms) with well-defined molecular weights (Mns) and low polydispersity (Mw/Mns). Removing the protecting Boc groups on the D-prolinol ester pendants leads to the formation of helical poly-1m-As, which showed high optical activity. Furthermore, the poly-1m-As showed high catalytic ability on asymmetric Michael addition reaction (up to 76% ee and 94/6 dr). Both the enantioselectivity and diastereoselectivity of the Michael addition reaction were increased comparing to D-prolinol as catalyst. Moreover, the helical polycarbene catalyst can be easily recovered and reused at least four times without significant loss of its enantioselectivity and diastereoselectivity.

Published in Catalysts

ISSN: 2073-4344 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Chemical technology; Science: Chemistry
Website: https://www.mdpi.com/journal/catalysts

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