Synthesis, Characterization, and Catalytic Activity of Cationic NHC Gold(III) Pyridine Complexes

Abstract

A series of cationic gold(I/III) pyridine complexes of the type [(L)Au(pyr)](PF 6 ) and [(L)AuCl 2 (pyr)](PF 6 ), where L = IPr, (1, 5); L = IMes (2, 6); L = I t Bu, (3, 7); L = ICy (4, 8); and L = PPh 3 , (9, 10), were synthesized and characterized by NMR spectroscopy and single-crystal X-ray diffraction. The stability of the new complexes and their catalytic activity in five well-established organic transformations were assessed.

Click-tailed coumarins with potent and selective inhibitory action against the tumor-associated carbonic anhydrases IX and XII

“…25 79.4, 79.8, 102.7, 113.7, 113.8, 113.9, 130.4, 145.1, 156.0, 161.0, 161.1 75.8, 79.0, 115.3, 121.9, 129.8, 157.9. Experimental in agreement with reported data.…”

“…Prop-2-ynylsulfanyl-benzene 20was obtained according the general procedure 2 earlier reported. 25 The reaction mixture was stirred at rt for 2 h to give the titled compound 20.…”

“…Phenyl-prop-2-ynyl-amine 21was obtained according the general procedure 2 earlier reported. 25 The reaction mixture was stirred at rt for 4 h and the obtained oil was purified by silica gel column chromatography eluting with EtOAc/petroleum ether 1:20 to afford the title compounds 21.…”

A Nucleophilic Gold(III) Carbene Complex

“…Accordingly, p donation from the carbene substituents [4][5][6] or enhanced p backdonation from the Au center, [7] were recently distinguished as the main stabilization modes of the electrophilic carbene center ( Figure 1). Thus,i ti sl ogical to contemplate the structures and reactivity of new Au III carbene complexes as acounterpoint to and extension of that for Au I species.S of ar only af ew Au III complexes featuring N-heterocyclic carbenes (NHC) as ancillary ligands have been reported [12] but structurally characterized Au III complexes featuring reactive carbene moieties remain unknown. Thus,i ti sl ogical to contemplate the structures and reactivity of new Au III carbene complexes as acounterpoint to and extension of that for Au I species.S of ar only af ew Au III complexes featuring N-heterocyclic carbenes (NHC) as ancillary ligands have been reported [12] but structurally characterized Au III complexes featuring reactive carbene moieties remain unknown.…”

Strategic Approach on N‐Oxides in Gold Catalysis – A Case Study

“…Noteworthy, only a few known pyridine gold(I) complexes are published to date. [8] For an effective synthesis, one equivalent of the gold(I) complex Ph 3 PAuNTf 2 ([Au] = 0.034 mmol/ml) was treated with one equivalent of a pyridine derivative in DCM at 25 8C for 3 h (Scheme 1). With respect to the pyridine derivatives, representatives of commonly used N-oxides and pyridines which are characterized by varying electronic or steric effects were chosen.…”