Our approach is delineated in Scheme 2 and relies on a versatile radical chemistry of xanthates we have developed over the past few years. 5 The key aspect is the degeneracy of the reaction of radical 5 with its xanthate precursor 3. This reactive intermediate is therefore not irreversibly consumed and acquires a comparatively long lifetime, allowing it to overcome both the rotational barrier of the amide linkage (equilibrium between 5a and 5b) and the quite slow ...
