Issue 31, 2018

A quantification scheme for non-covalent interactions in the enantio-controlling transition states in asymmetric catalysis

Abstract

The origin of enantioselectivity in asymmetric catalysis is attributed to the energy difference between lower and higher energy diastereomeric transition states, which are respectively responsible for the formation of major and minor enantiomers. Although the increase in the number of transition state models emphasizes the role of weak non-covalent interactions in asymmetric induction, the strength of such interactions is seldom quantified. Through this article, we propose a simple and effective method of quantifying the total non-covalent interaction in stereocontrolling transition states belonging to a group of three representative asymmetric catalytic reactions involving chiral phosphoric acids. Our method relies on rational partitioning of a given transition state into two (or three) sub-units, such that the complex network of intramolecular interactions can be ameliorated to a set of intermolecular interactions between two sub-units. The computed strength of interaction obtained using the counterpoise (CP) method on suitably partitioned transition states provides improved estimates of non-covalent interactions, which are also devoid of basis set superposition error (BSSE). It has been noted that catalysts decorated with larger aromatic arms provide cumulative non-covalent interactions (C–H⋯π, N–H⋯π and π⋯π) to the tune of 10 to 15 kcal mol−1. Fine-tuning of the magnitude and nature of these interactions can provide valuable avenues in the design of asymmetric catalysts.

Graphical abstract: A quantification scheme for non-covalent interactions in the enantio-controlling transition states in asymmetric catalysis

Supplementary files

Article information

Article type
Paper
Submitted
17 Cax 2018
Accepted
12 Qad 2018
First published
12 Qad 2018

Org. Biomol. Chem., 2018,16, 5643-5652

A quantification scheme for non-covalent interactions in the enantio-controlling transition states in asymmetric catalysis

S. Malakar, S. V. Shree Sowndarya and R. B. Sunoj, Org. Biomol. Chem., 2018, 16, 5643 DOI: 10.1039/C8OB01158C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements