A Totally Radical Approach to the Control of Stereochemistry: Coupling of Prochiral Radicals with Chiral Nitroxyl Radicals

Abstract

A Yo hv [hS PhS = I Ph a) [Cp(Co)~Feh, hv b) CrS04, 0 "C a) 65 o/o C) 78 Yo 1 -p h +~+ & I b) 10 % Me The development of new, selective )-NHNH~ ~

Readily Accessible Oxazolidine Nitroxyl Radicals: Bifunctional Cocatalysts for Simplified Copper Based Aerobic Oxidation

“…While the synthesis of TOXYLs is known, [15] they are yet to be studied as oxidation catalysts, hence it was essential to establish competence in this regard, prior to commencing studies with homochiral catalysts. Herein we report the synthesis of a number of novel bifunctional TOXYL derivatives 2 and describe their application to the aerobic oxidation of alcohols.…”

Nitroxide decomposition: Implications toward nitroxide design for applications in living free‐radical polymerization

“…7 In organic chemistry, nitroxides have been used in kinetic studies, [8][9][10][11] as oxidizing species in the form of the corresponding N-oxo ammonium salts, [12][13][14][15][16][17][18][19][20][21][22][23] as temporary caps for transient carbon radicals, [24][25][26][27][28][29][30][31] and as probes for stereocontrol with prochiral carbon radicals. [32][33][34][35][36] In polymer chemistry, nitroxide-mediated polymerization (NMP) [37][38][39][40][41][42][43][44][45][46][47] has become popular as a method for preparing living polymers [48][49][50][51] under mild, chemoselective conditions with good control over both the polydispersity and molecular weight. In designing nitroxides for applications in NMP, much attention has been directed toward fine-tuning the nitroxide structure to lower the bond dissociation energy (BDE) of the transient Nalkox...…”

Unique Stereoselective Homolytic C−O Bond Activation in Diketopiperazine‐Derived Alkoxyamines by Adjacent Amide Pyramidalization

“…Diastereomeric excess has been previously noted for stereoisomeric alkoxyamines upon reversible homolysis and coupling, by which an achiral nitroxide radical couples to a chiral carbon‐centered radical (Figure A). However, none of the so‐far‐investigated diastereomeric acyclic alkoxyamines 8 – 10 , described by Marque and Ananchenko, Moad and Rizzardo, and Georges, exhibited large diastereomeric preferences on thermal homolysis/radical coupling reactions.…”