title: Multifunctional phosphine stabilized gold nanoparticles: an active catalytic system for three-component coupling reaction.
abstract: Multifunctional phosphine based ligands, 1,1,1-tris(diphenylphosphinomethyl)ethane [CH3C(CH2 PPh2)3][P3] and 1,1,1-tris(diphenylphosphinomethyl)ethane trisulphide [CH3C(CH2P(S)Ph2)3][P3S3] have been introduced to stabilize Au(o)-nanoparticles having small core diameter and narrow size distribution. The Au(o)-nanoparticles were synthesized by the reduction of HAuCl4 precursor with NaBH4 in the presence of ligand P3 or P3S3 using two phases, one pot reaction at room temperature. The Au(o)-nanoparticles exhibit face centered cubic (fcc) lattice having different crystalline shape i.e., single crystallite stabilized by P3 while P3S3 forms decahedral shapes. Surface plasmon bands at -520 nm and TEM study indicate particle size below 2 and 4 nm for Au(o)-nanoparticles stabilized by P3 and P3S3 respectively, which are attributable to the stronger interaction of Au(o) (Soft) with P (Soft) than Au(o) (Soft) with S (less Softer than P). Au(o)-nanoparticles stabilized by P3S3 shows higher thermal stability than that of P3. The synthesized Au(o)-nanoparticles serve as an efficient catalyst for one-pot, three-component (A3) coupling of an aldehyde, an amine and an alkyne via C-H alkyne-activation to synthesize propargylamines (85-96%) without any additives and precaution to exclude air.
authors.affiliation: Materials Science Division, CSIR-North East Institute of Science and Technology, Jorhat 785 006, Assam, India.
authors.forename: Bibek Jyoti
authors.initials: BJ
authors.lastname: Borah
authors.forename: Subrat Jyoti
authors.initials: SJ
authors.lastname: Borah
authors.forename: Dipak Kumar
authors.initials: DK
authors.lastname: Dutta
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000588:Amines / Q000138:chemical synthesis*; D002384:Catalysis; D005079:Excipients / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D053768:Metal Nanoparticles; D010720:Phosphines / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D000588:Amines; D005079:Excipients; D010720:Phosphines; D006046:Gold; C044646:phosphine