Online HPLC Analysis of Buchwald-Hartwig Aminations from Within an Inert Environment

18 August 2020, Version 1

Abstract

We have developed a reaction monitoring platform capable of automated sampling and online HPLC analysis to generate temporal profiles for reactions performed from within a glovebox. The device allows for facile reaction progress analysis to aid in mechanistic studies of air-sensitive chemical transformations. The platform has demonstrated high reproducibility regarding sample mixing, dilution, delivery, and analysis. We employed the sampling platform to acquire temporal profiles for a series of Buchwald-Hartwig aminations. Parallel coupling reactions using iodobenzene and bromobenzene both exhibit complex kinetics. A competition reaction including both aryl halides demonstrated high selectivity for iodobenzene indicative of catalyst monopoly. The temporal profile for the difunctionalized substrate 1,4-iodobromobenzene was unexpected based a priori and is indicative of a distinct underlying mechanism. We attribute this unanticipated reactivity to intramolecular catalysts transfer through the π system as seen in “living” polymerization transfer catalyst systems. This automated sampling platform has greatly increased mechanistic understanding by performing only a small subset of experiments.

Content

Supplementary materials

Glovebox DI SI Final chemrxiv

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.