Issue 48, 2017

A computational investigation of the solvent-dependent enantioselective intramolecular Morita–Baylis–Hillman reaction of enones

Abstract

The intramolecular Morita–Baylis–Hillman reaction of β-mono and β,β-disubstituted enones shows high yields and stereo-selective products when the reaction is performed in the presence of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as a solvent. In this work, we carried out a computational study using the density functional Becke 3-(B3) parameter exchange and the Lee–Yang–Parr (LYP) correlation functional and 6-31+G* basis set. Two major steps i.e. C–C bond formation and proton transfer were analysed using different pathways. The calculations show a very low barrier (ΔG = 0.23 kcal mol−1) for C–C bond formation in the case of an experimentally dominant product. For this pathway the subsequent proton transfer via the HFIP step has a barrier of 26.98 kcal mol−1. The same has been confirmed using a Molecular Electrostatic Potential (MESP), which shows a negative region in between C⋯C in the transition state. In spite of high barriers for proton transfer, the intermediate products formed in this reaction pathway are thermodynamically more stable in comparison with other pathways. The thermodynamic stability of the final product in this pathway is observed to surpass all other effects in the presence of HFIP, thereby corroborating the experimentally observed enantioselectivity.

Graphical abstract: A computational investigation of the solvent-dependent enantioselective intramolecular Morita–Baylis–Hillman reaction of enones

Supplementary files

Article information

Article type
Paper
Submitted
14 اگست 2017
Accepted
15 نومبر 2017
First published
15 نومبر 2017

Org. Biomol. Chem., 2017,15, 10212-10220

A computational investigation of the solvent-dependent enantioselective intramolecular Morita–Baylis–Hillman reaction of enones

N. K. Singh, B. Satpathi, P. Balanarayan and S. S. V. Ramasastry, Org. Biomol. Chem., 2017, 15, 10212 DOI: 10.1039/C7OB02025B

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