New cationic coinage metal complexes featuring silyl group functionalized phosphine: syntheses, structures and catalytic studies in alkyne-azide cycloaddition reactions

• Published in: Dalton transactions : an international journal of inorganic chemistry 2023-10, Vol.52 (42), p.15549-15561
• Main Authors: Sahoo, Amiya Kumar, Kumar Sahoo, Ashish, Das, Bhagyashree, Panda, Subhra Jyoti, Purohit, Chandra Shekhar, Doddi, Adinarayana
• Format: Article
• Language: English
• Subjects: Alkynes; Cations; Coordination compounds; Copper; Copper chloride; Copper compounds; Cycloaddition; Molecular structure; Phosphines; Silver; Single crystals; Spectrum analysis; Triazoles
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d3dt01692g

A series of coinage metal complexes bearing rarely explored ortho -silylated phosphine is reported. The treatment of diphenyl(2-(trimethylsilyl)phenyl)phosphine ( 1 ) with CuCl and [Cu(CH 3 CN) 4 ]BF 4 furnished the corresponding neutral [( 1 )CuCl] 2 ( 2 ) and mono-cationic [( 1 ) 2 Cu(CH 3 CN)]BF 4 ( 3 ) complexes, respectively. The reactions of 1 with AgX (X = BF 4 − , NO 3 − ) in 2 : 1 ratio furnished the corresponding mono cationic dicoordinate silver( i ) complexes of the type [( 1 ) 2 Ag]X (X = BF 4 − ( 4a ), NO 3 − ( 4b )). The ortho -silylated phosphine ligand ( 1 ) was conveniently converted into the corresponding sulfide ( 5a ) and selenide ( 5b ) species, and their reactions with [Cu(CH 3 CN) 4 ]BF 4 yielded mono-cationic, homoleptic tris(silylphosphinochalcogenide)copper( i ) complexes of the type [( 5a / 5b ) 3 Cu]BF 4 ( 6a / 6b ). The molecular structures of 2-4 and 6 were established by single-crystal X-ray diffraction analysis. The copper complexes 2 , 3 , and 6a were employed as catalysts in azide-alkyne cycloaddition reactions. Among these complexes, 3 was extensively used in the preparation of various mono- and bis-triazoles consisting of tolyl, benzyl, carbazolyl, and propargylic ether groups. Three sets of substituted triazole derivatives were achieved under mild conditions by employing copper( i ) catalytic systems. The mechanistic studies indicated the formation of a heteroleptic copper( i ) triazolide intermediate which was detected by high-resolution mass spectral analysis. A series of coinage metal complexes bearing rarely explored ortho -silylated phosphine is reported.