Azide alkyne cycloaddition facilitated by hexanuclear rhenium chalcogenide cluster complexes

作者：Knott Stanley A; Templeton Jeffrey N; Durham Jessica L; Howard Angela M; McDonald Robert; Szczepura Lisa F^*

来源：Dalton Transactions, 2013, 42(22): 8132-8139.

DOI：10.1039/c3dt50436k

Two hexanuclear rhenium clusters containing azide ligands, [Re6Se8(PEt3)(5)(N-3)]BF4 and [Re6Se8(PEt3)(4)(N-3)(2)], were synthesized from the analogous pyridine complexes and fully characterized. Studies show that [Re6Se8(PEt3)(5)(N-3)]BF4 reacts with activated alkynes, dimethyl acetylenedicarboxylate and methyl 4-hydroxy-hex-2-yneoate, to form the triazolate cluster complexes [Re6Se8(PEt3)(5)(L1 or L2)]BF4 (where L1 = 4,5-bis(methoxycarbonyl)-1,2,3-triazol-2-yl and L2 = 4-methoxycarbonyl-5-(1-propanol)-1,2,3-triazol-2-yl). The bis-triazolato complex, cis-[Re6Se8(PEt3)(4)(L1)(2)] was also prepared via a similar reaction starting with cis-[Re6Se8(PEt3)(4)(N-3)(2)] demonstrating that these clusters can promote two azide moieties to undergo heterocyclic ring formation. The structures of [Re6Se8(PEt3)(5)(N-3)]BF4, [Re6Se8(PEt3)(4)(N-3)(2)], and [Re6Se8-(PEt3)(5)(L1)](BF4), were determined by single-crystal X-ray diffraction analysis. In addition, studies involving the alkylation of [Re6Se8(PEt3)(5)(L1)]BF4 with benzyl bromide and methyl iodide are reported.

• 出版日期2013