Highly controlling selectivity of copper(I)-catalyzed azide/alkyne cycloaddition (CuAAC) between sulfonyl azids and normal alkynes or propynoates

Synthesis and characterization of redox active cyrhetrene–triazole click products

“…3 Our first attempt at the copper-catalysed azide/alkyne cycloaddition of 3 was achieved using the conditions we have previously reported for the manganese variant of cyrhetrene {Scheme 1, (iii)}. 3,19,20 Reassuringly, the transformation of 2 into 3 was complete in 8 hours under these mild conditions; purification of 3 via silica gel flash column chromatography afforded 3 as a white crystalline solid in good yield and high purity (Scheme 1). [a] An extra band is observed in the asymmetric region for samples run in the solid state as a result of hindered rotation about the Re-Cp centroid and a subsequent descent in symmetry.…”

Stereoselective 1,3-Insertions of Rhodium(II) Azavinyl Carbenes

“…Recent additions to the rapidly growing list of applications of 1-sulfonyl-1,2,3-triazoles under Rh(II) catalysis include transannulations and cyclopropanations, 9 C–H insertion, 10 ketone formation with water and O–H insertions/rearrangements, 11 ring expansions, 8,12 rearrangement reactions, 12a and arylation with boronic acids. 13 Given the efficiency of both the Cu(I)-catalyzed formation of triazole 1 5 and its subsequent Rh(II)-catalyzed denitrogenative reactions, 8–13 this sequence of simple transformations can be viewed as a two-step regio- and stereoselective bis-functionalization of the acetylenic backbone. …”

Synthesis of 1-arylsulfonyl-1,2,3-triazoles from (Z)-arylvinyl bromides by sequential elimination–cycloaddition reaction

“…[18][19][20] Thus, the efficient synthetic approach to N-sulfonyltriazoles by CuAAC was rarely reported. 21 Fokin and Chang have described a useful copper-catalyzed approach to N-sulfonyltriazoles carried out at low temperature in the presence of 2,6-lutidine. 22 Fu and coworkers reported the formation of N-sulfonyl-1,2,3-triazoles using CuBr-PhSMe as efficient catalyst.…”

“…23 N-sulfonyltriazoles could also be obtained using Cu(OAc) 2 ·H 2 O -2-aminophenol catalysis. 21 N-Sulfonyl-1,2,3-triazoles could also be prepared by alternative reaction of 1H-1,2,3-triazoles with sulfonyl chlorides, giving access to compounds that are not available by CuAAC approach. 16,24 (Z)-Arylvinyl bromides, readily available by debrominative decarboxylation of cinnamic acid dibromides, 25 have been exploited as useful precursors of alkynes in many organic transformations.…”

“…White solid, mp 107-109°C (mp 104-105°C,21 mp 107-108°C,22 mp 108-109°C23 ). IR spectrum, ν, cm -1 : 3142, 1595, 1388 (SO 2 ), 1198, 1171 (SO 2 ).…”