Gold‐Catalyzed Direct C(sp³)−H Acetoxylation of Saturated Hydrocarbons

Abstract

In this communication we report our studies towards the development of a gold‐catalyzed direct acetoxylation of C(sp3)−H bonds. We achieve this through the use of the hypervalent iodine reagent PhI(OAc)2 in combination with a simple gold salt (HAuBr4) as the catalyst. Through a comparison of the reactivities of cyclooctane and adamantane we judge the reaction to proceed via hydride transfer. This is further substantiated through computational studies of the relative energies for the anions, radicals and cations derived from C−H bond cleavage of cyclooctane and adamantane relevant to the C−H cleaving step.

Site selective gold(i)-catalysed benzylic C–H amination via an intermolecular hydride transfer to triazolinediones

“…Such hydride transfers are known for carbocationic reagents, but hydride transfer to nitrogens are rare. 17 Moreover, well-controlled hydride transfer catalytic pathways are usually confined to intramolecular reactions, 18 or to enzymatic reactions with hydride-accepting co-factors such as NAD + or FAD. 19 The difference in reaction rate between different substrates as observed here can be quite readily rationalized according to this carbocationic pathway, and the DFT-calculated energies for different substrates are in complete agreement with experiments (see ESI † ).…”

Creating, Preserving, and Directing Carboxylate Radicals in Ni-Catalyzed C(sp3)–H Acyloxylation of Ethers, Ketones, and Alkanes with Diacyl Peroxides

“…The direct C–H functionalization of nonactivated alkanes is still relatively scarce due to their intrinsic low reactivity. Acyloxylation of C­(sp 3 )–H bonds in alkanes was achieved with [Au]/PIDA, Co­(OAc) 2 /I 2 /NHPI/O 2 /HNO 3 , H 2 O 2 /TFA, Selectfluor/CuBr 2 /pentanenitrile, TFAN/TFA, RuCl 3 /AcOOH/TFA, Fe­(III)/O 2 /TFA/ hv , and [Mn]/H 2 O 2 . , In some cases, it was difficult to avoid overoxidation of the product, which led to allyl esters (CuTPP/DTBP, Cu­(OAc) 2 / TBHP, [(BPI)­CuCl]/ DTBP, and CuO/DTBP).…”

Valence Tautomerism Induced Proton Coupled Electron Transfer:X−H Bond Oxidation with a Dinuclear Au(II) Hydroxide Complex

“…An interesting feature of this Based on our interest in oxidation chemistry using adducts of gold and oxygen for activating C(sp 3 )À H bonds, we recently reported the acetoxylation of saturated hydrocarbons using simple Au salts and the oxidant PhI(OAc) 2 . [15] A complementary development that showcases the potential of gold complexes to be efficient catalysts for transformations involving one-electron steps is the diversity of photochemical reactions with gold. [3c-e,h,i,l-p,16] Representative examples include dinuclear phosphine Au I complexes.…”