Modifying Positional Selectivity in C-H Functionalization Reactions with Nitrogen-Centered Radicals: Generalizable Approaches to 1,6-Hydrogen-Atom Transfer Processes
© 2020 Georg Thieme Verlag. All rights reserved. Nitrogen-centered radicals are powerful reaction intermediates owing in part to their ability to guide position-selective C(sp 3)-H functionalization reactions. Typically, these reactive species dictate the site of functionalization by preferentially engaging in 1,5-hydrogen-atom transfer (1,5-HAT) processes. Broadly relevant approaches to alter the site-selectivity of HAT pathways would be valuable because they could be paired with a variety of tactics to install diverse functional groups. Yet, until recently, there have been no generalizable strategies to modify the position-selectivity observed in these HAT processes. This Synpacts article reviews transformations in which nitrogen-centered radicals preferentially react through 1,6-HAT pathways. Specific attention will be focused on strategies that employ alcohol- and amine-anchored sulfamate esters and sulfamides as templates to achieve otherwise rare γ-selective functionalization reactions. 1 Introduction 2 Transformations that Rely on Structural Constraints or Weakened C-H Bonds to Favor 1,6-HAT Processes 3 Sulfamate Esters Engage Selective 1,6-HAT Processes 4 Expansion to 1,6-HAT Processes with Masked Amine Substrates 5 Conclusions and Outlook.
Short, MA; Blackburn, JM; Roizen, JL
Volume / Issue
Start / End Page
Electronic International Standard Serial Number (EISSN)
International Standard Serial Number (ISSN)
Digital Object Identifier (DOI)