Alkene Isomerization Catalyzed by a Mn(I) Bisphosphine Borohydride Complex

26 June 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

An additive-free manganese-catalyzed isomerization of terminal alkenes to internal alkenes is described. This reaction is atom economic, implementing an inexpensive, non-precious metal catalyst. The most efficient catalyst is the borohydride complex cis-[Mn(dippe)(CO)2(κ2-BH4)]. This catalyst operates at room temperature with a catalyst loading of 2.5 mol %. A variety of terminal alkenes are effectively and selectively transformed to the respective internal E-alkenes. Preliminary results show chain walking isomerization at elevated temperature. Mechanistic studies were carried out including stochiometric reactions and in situ NMR analysis. These experiments are flanked by computational studies. Based on these, the catalytic process is initiated by liberation of “BH3” as a hydroborated alkene. The catalytic process is initiated by double bond insertion into an M–H species leading to an alkyl metal intermediate, followed by β-hydride elimination at the opposite position to afford the isomerization product.

Keywords

manganese
borohydride
alkenes
DFT calculations
isomerization

Supplementary materials

Title
Description
Actions
Title
Alkene Isomerization Catalyzed by a Mn(I) Bisphosphine Borohydride Complex
Description
Synthetic procedures, 1H, 13C{1H}, and 31P{H} NMR spectra of all compounds and complete computational details
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.