Photo-induced copper-catalyzed alkynylation and amination of remote unactivated C(sp³)-H bonds

Abstract

A method for remote radical C–H alkynylation and amination of diverse aliphatic alcohols has been developed. The reaction features an copper nucleophile complex formed in situ as photocatalyst, which reduces...

Photo-induced copper-catalyzed sequential 1,n-HAT enabling the formation of cyclobutanols

“…The use of substrates containing unactivated halogen−carbon bonds is less studied because of the relatively high reduction potential and putative reactivity of the resulting unstabilized sp 3 carbon radical. We have been interested in copper (Cu)-photocatalysis using aliphatic halide as the radical precursor 39 – 41 . Cu complexes have displayed highly tunable redox properties in their excited states, diverse ligand types, and the free conversion of multiple oxidation states 42 – 45 .…”

“…Despite this progress, as far as we know, examples of the use of readily available aliphatic halides as the radical precursor under visible-light photocatalysis for intermolecular cascade cyclization en route to four-membered rings are lacking. During our investigation on photoinduced Cu-catalyzed remote C − H alkynlylation with iodomethylsilyl alcohols 39 , we isolated an unexpected cyclized compound 3a as a minor product when we employed an electron-deficient aryl alkyne. Notably, 3a is a product of a HAT/vinyl radical formation/cyclization cascade reaction that involves the functionalization of two C( sp 3 )−H bonds.…”

Recent Advances in Visible-Light-Promoted Copper Catalysis in Organic Reactions

“…61a In a related study, C-H bond of N- Recently, with ongoing efforts, Zhang group and co-worker have achieved visible-light-promoted, copper-catalyzed the remote radical C-H alkynylation and amination of β, γ, and δ positions in aliphatic ethers (Scheme 40). 62 The transformation features a copper nucleophile complex formed in situ as a photocatalyst, which could reduce the silicon-tethered aliphatic iodide to alkyl radical for initiating 1, n-hydrogen atom transfer.…”

“…The [L7-Cu(I)] complex is formed in situ, which undergoes transmetallation with [Li-azole] Recently, with ongoing efforts, Zhang and co-workers achieved visible-light-promoted, copper-catalyzed remote radical C-H alkynylation and amination of -, -, and -positions in aliphatic ethers (Scheme 40). 62 The transformation features a copper nucleophile complex formed in situ…”

Soy protein isolate-carboxymethyl cellulose conjugates with pH sensitivity for sustained avermectin release

“…Pesticides are commonly used in agriculture to control diseases, pests and weeds from affecting crops [1]. Annual worldwide usage of pesticides is in millions of tons, without which 40% of crop would be lost [2].…”