Lewis acid-catalyzed diastereoselective ene reaction of thioindolinones with bicyclobutanes

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

Abstract

Bicyclo[1.1.0]butanes (BCBs), featuring two fused cyclopropane rings, have found widespread application in organic synthesis. Their versatile reactivity towards radicals, nucleophiles, cations, and carbenes makes them suitable for various reactions, including ring-opening and annulation strategies. Despite this versatility, their potential as enophiles in an ene reaction remains underexplored. Considering this and given the challenges of achieving diasteroselectivity in ring-opening reactions of BCBs, herein, we present a unique method utilizing BCBs as enophiles in a mild and diastereoselective Sc(OTf)3-catalyzed ene reaction with thioindolinones, delivering 1,3-disubstituted cyclobutane derivatives in high yields and excellent regio- and diastereoselectivity. Notably, structurally different thione derivatives underwent diastereoselective addition to BCBs, affording the corresponding cyclobutanes. The synthesized thioindole-substituted cyclobutanes could serve as a versatile tool for subsequent functional group manipulations.

Keywords

Bicyclobutanes
ene reaction
Lewis acid catalysis
Strain release
Thioindolinones

Supplementary materials

Title
Description
Actions
Title
Supporting Information
Description
Details on experimental procedures, mechanistic experiments, characterization data of all the 1,3-disubstituted cyclobutanes and X-ray data of 8.
Actions

Supplementary weblinks

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.