Sterically Demanding Novel Triazole Based Tertiary Phosphines: Synthesis, Transition Metal Chemistry and Catalytic Applications

• Published in: European journal of inorganic chemistry 2023-09, Vol.26 (25), p.n/a
• Main Authors: Kote, Basvaraj S., Mohite, Manali A., Mondal, Dipanjan, Pandey, Madhusudan K., Balakrishna, Maravanji S.
• Format: Article
• Language: English
• Subjects: amination reaction; Chemical synthesis; Hydrogen peroxide; Inorganic chemistry; metal complexes; Molecular structure; P ligands; Palladium; Phosphines; Selenium; Suzuki-Miyaura reaction; Transition metals; Triazoles; X-ray diffraction
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.202300291

Sterically demanding 2,6‐dibenzhydryl‐4‐methylphenyl and 1,2,3‐triazole based tertiary phosphines, [Ar*{1,2,3‐N3C(Ph)C(PR2)}] (R=Ph, 3; R=iPr, 4) were obtained by the temperature‐controlled lithiation of 1‐(2,6‐dibenzydryl‐4‐methyl)‐5‐iodo‐4‐phenyl‐1H‐1,2,3‐triazole (2) followed by the reaction with R2PCl (R=Ph, iPr). Treatment of 3 with H2O2, elemental sulfur and selenium yielded chalcogenides [Ar*{1,2,3‐N3C(Ph)C(P(E)Ph2)}] (E=O, 5; E=S, 6; E=Se, 7). The reaction of 3 with [Pd(COD)Cl2] in 1 : 1 molar ratio, afforded dimeric complex [Pd(μ2‐Cl)Cl{Ar*{1,2,3‐N3C(Ph)C(PPh2)}‐κ1‐P}]2 (8), whereas the reactions of 3 and 4 with [Pd(η3‐C3H5)Cl]2 in 2 : 1 molar ratios produced complexes [Pd(η3‐C3H5)Cl{Ar*{1,2,3‐N3C(Ph)C(PR2)}‐κ1‐P}] (R=Ph, 9; R=iPr, 10). Treatment of 3 with [Pd(OAc)2] in 1 : 1 molar ratio afforded a rare trinuclear complex [{Pd3(OAc)4}{Ar*{1,2,3‐N3C(C6H4)C(PPh2)}‐κ2‐C,P}2] (11). Treatment of 3 and 4 with [AuCl(SMe2)] resulted in [AuCl{Ar*{1,2,3‐N3C(Ph)C(PR2)}‐κ1‐P}] (R=Ph, 12; R=iPr, 13). Bulky phosphine 4 was very effective in Suzuki‐Miyaura coupling and amination reactions with very low catalyst loading. Molecular structures of 3–5, and 8–13 were confirmed by single‐crystal X‐ray diffraction studies. This paper describes the synthesis, transition metal chemistry and catalytic applications of sterically demanding novel triazole based tertiary phosphines.