Copper(I)‐Catalyzed Interrupted Click/Sulfenylation Cascade: One‐Pot Synthesis of Sulfur Cycle Fused 1,2,3‐Triazoles

Abstract

of main observation and conclusion Herein, we report a practical protocol for the synthesis of sulfur cycle fused 1,2,3-triazoles through a copper(I)-catalyzed tandem click/intramolecular sulfenylation reaction. The reaction proceeded via a copper-catalyzed alkyne azide cycloaddition, followed by interception of the in situ formed cuprate-triazole intermediate with p-toluenesulfonothioate. This reaction shows broad substrate scope, complete regioselectivity, and excellent functional group tolerance under mild reaction conditions. www.cjc.wiley-vch.de

Interrupted CuAAC‐Thiolation for the Construction of 1,2,3‐Triazole‐Fused Eight‐Membered Heterocycles from O‐/N‐Propargyl derived Benzyl Thiosulfonates with Organic Azides

“…On the basis of the above experimental results and the literature evidence, [10a,11b,20] a plausible mechanism for this cascade process is proposed (Scheme 4). Initially, the actual copper‐catalytic species (CuL n ; L: 1,10‐phen ) [20a] may generated from CuI‐1,10‐phen, which may activate the π‐system to form the copper(I) acetylide ( A ) [20a] intermediate.…”

“…The oxidative‐protonation of the intermediary ( B ) might be realized to uncyclized product 3 a . Subsequently, the effective coordination of Cu−S in B may facilitate giving defined Cu(III) complex ( C ) [10a,11b] through the oxidative‐addition process. Further, reductive‐elimination of organocopper(III) precursor ( C ) [20c] would allow the formation of C−S bond to give the desired 3 aa and to regenerate active catalyst species for the further catalytic process.…”

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

“…Many aliphatic, aromatic, thiophenyl-, and ferrocenyl-substituted acetylenes were found to give excellent results in the reaction with aliphatic tosylthio azides 74 with different chain length (n = 1-3). For azides with n = 3, the reaction was performed using alkynes bearing rather complex R 2 substituents, such as tyrosine, glucose, clofibrate, vitamin E, estrone, and oleanane triterpenes, which tolerated the reaction conditions and afforded the corresponding triazoles 77 fused with a six-membered sulfur-containing cycle (Scheme 23) [52]. Some reactions were performed to screen the reaction mechanism in detail.…”

“…This subsequently cyclized with the azide 73 to afford the triazole cuprate intermediate 79 . Finally, the resulting intermediate proceeds through an oxidative addition and reductive elimination sequence to give the final product, followed by the next cycle ( Scheme 24 ) [ 52 ].…”

Synthesis of 1‐(3H)isobenzofuranone compounds by tin powder promoted cascade condensation reaction

“…[ 3 ] Thus, considerable attention has been paid to the methodological development of the construction of phthalide derivatives. [ 4 ] Up to now, many synthetic approaches have been developed for the synthesis of phthalides derivatives, which can be classified as follows: addition/cyclization reaction of organometallic reagent with aldehydes/ketones, [ 5 ] transition metal catalyzed intramolecular hydroacylation of ketones, [ 6 ] coupling reaction of transition metal‐catalyzed aryl boric acids with 2‐formyl benzoate alkyl esters, [ 7 ] copper(I)‐catalyzed interrupted click reaction, [ 8 ] and other methods. [ 9 ] Among these various methods, metal promoted addition/cyclization process of allyl bromides with 2‐formylbenzoic acids or esters is more direct and convenient way without the use of transition metal catalysts.…”