Introducing Alkene Moieties via Iterative Carbenoid Insertions: Vinylene Homologation of Organoboronates

08 June 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The Matteson homologation of organoboronates has been an attractive approach for constructing aliphatic carbon chains via iterative insertion of carbenoids. However, the corresponding homologation that can introduce alkene moieties to molecular backbones remains elusive. Here we report the development of a stereoselective vinylene homologation of various alkyl and aryl boronates. The reaction is enabled by diastereoselective consecutive insertion of a silyl- and an alkoxy-substituted carbenoid, followed by a Peterson-type elimination. Diverse alkenyl boronates can be obtained in good yield and good to excellent trans selectivity. Density functional theory (DFT) calculations revealed the origin of diastereoselectivity in carbenoid insertion and how Lewis acids with different sulfide binding affinities affect the competing SN2- and SN1-type 1,2-boronate migration pathways with distinct levels of stereospecificity. This protocol has been successfully applied to programmable synthesis of piperamide-family natural products by merging with the methylene homologation. Guided by the mechanistic understanding, preliminary success has been achieved with the cis-selective vinylene homologation enabled by oxyphilic Lewis acids.


Vinylene Homologation
Boron Chemistry

Supplementary materials

Supporting Information
The experimental details of the work


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.