Palladium-catalyzed intermolecular amination of unactivated C(sp³)–H bonds via a cleavable directing group

Abstract

Palladium-catalyzed intermolecular amination of unactivated C(sp)-H bonds was developed. Using NFSI as both the amino source and the oxidant, this protocol operates under mild conditions with excellent terminal selectivity and a broad substrate scope. Moreover, the directing group can be easily removed to produce 1,2-amino alcohols.

Selective C(sp3)−H and C(sp2)−H Fluorination of Alcohols Using Practical Auxiliaries

“…In principle, C−F bond formation is usually more sluggish than the competing reductive eliminations from high‐valent Pd IV species because of the poor nucleophilicity of fluorine anion. Indeed, the fluorinating reagent NFSI was mainly used as an oxidant for the formation of other chemical bonds such as C−O and C−N bonds in previous C(sp 3 )−H bond functionalizations of alcohols . Only cyclic methylene C(sp 3 )−H bonds were fluorinated in moderate yields as side reactions.…”

Diastereoselective palladium-catalyzed functionalization of prochiral C(sp3)–H bonds of aliphatic and alicyclic compounds

“…Dong illustrated the employment of oxime-based DGs for the oxygenation of diastereotopic C–H bonds in substrates 38a,d to afford the corresponding C–H oxygenated products 38b,c , and 38e (Scheme 18). 61,62 Liu revealed 63 the oxime DG-aided preparation of β-C–H fluorinated product 38f by using NFSI. Similarly, Lou and Xu reported the β-C–H fluorination of alicyclic alcohols and ketones by using N -pentafluorophenyl pyruvamide 64 a and O -acetic amide pinacolone oxime 64 b as the DG, which afforded the corresponding β-C–H fluorinated alicyclic alcohols 38g,h and ketone 38i .…”

sp3C–H activationvia exo-type directing groups

“…In 2017, Liu 22 a and Liu 22 b independently reported the Pd-catalyzed β-sulfonimidation of masked alcohols using NFSI as the oxidant and the nitrogen source ( Scheme 17 ). The 8-quinolyl-derived aldoxime was found to be the optimal exo DG in each work.…”