Preparation and characterization of novel six-membered cyclopalladated complexes of 2-benzylpyridine

Abstract

I. It consists of a unique zigzag chain structure in which the distorted [(C3H7)2NCS2T1]2 dimers are connected by interdimer Tl-S linkages such that one T1(I) is six-coordinate while the other is five-coordinate. Instead of an eight-membered ring, it exists as a distorted bipyramid with T1(I) atoms at the apices.Acknowledgment is made to the donors of the Petroleum Research Fund, administered by the American Chemical Society, for partial support of this research.Registry No. [Au(S2CN(C2H5)2)SCN]2, 79255-13-3; [Au(S2C-N(C2H5)2)2][Au(SCN)2], [Au(S2CN(C2H5)2)SeCN]2, 79255-15-5; [Au(S2CN(C2H5)2)2][Au(SeCN)2], 2)Br]2, 79255-18-8; [Au(S2CN(C2H5)2)2][AuBr2], 33916-73-3; [Au(S2CN(C2H5)2)I]2, 79255-19-9; [Au(S2CN(C2-H5)2)2][AuI2], 79255-20-2; [Au(S2CN(C2H5)2)2][Au(SCN)2Br2], 79255-22-4; [Au(S2CN(C4H,)2)SCN]2, 79255-23-5; [Au(S2CN-(C4H9)2)2][Au(SCN)2], [Ag(S2CN(C2H5)2)]6, 59859-16-4; [Au(S2CN(C2H5)2)]2, 66712-10-5; [Au(S2CN(C4H9)2)]2, 59306-90-0; (SCN)2, 505-14-6; (SeCN)2,27151-67-3; Br2, 7726-95-6; I2, 7553-56-2.

1H, 13C and 15N nuclear magnetic resonance coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with phenylpyridines

“…[13] The deshielding of H (6) [5,6,8 -10] and in the related Ni(II) bromide complex [Ni(2ppy)(2ppy * )Br] − H(6) coord = 0.79 ppm (in benzene-d 6 ). [41] The same phenomenon is predominant for the analogous H(6) atom in Au(III), Pd(II) and Pt(II) chloride complexes with many other 2-aryl pyridine derivatives, although the magnitudes of the H (6) coord parameters are usually smaller than in case of 2ppy (Table 2S, (6) coord = 0.08 ppm, [42] [Au(2-benzoyl-py)Cl 3 ]− H(6) coord = 0.01 ppm, [43] [Au(2-phenoxy-py)Cl 3 ] − H(6) coord = −0.06 ppm and [Au(2-phenylsulfanyl-py)Cl 3 ] − H(6) coord = −0.01 ppm, [44] trans-[Pd(2-benzyl-py) 2 Cl 2 ] − H(6) coord = 0.19 ppm, [45] trans-[Pd(2-(1-phenylethyl)-py) 2 Cl 2 ] − H(6) coord = 0.52 ppm, [46] trans-[Pd(2-(2-naphthyl)-py) 2 Cl 2 ] − H(6) coord = 0.20 ppm, [47] [Pd(2-(8-quinolyl)-py)(P(CH 2 CH 3 ) 3 (2) coord = 0.15 ppm, [37] although not for trans-[Pd(4-phenylpyrimidine) 2 Cl 2 ] (4-phenylpyrimidine being an analogue of 2ppy), where H(2) coord = 0.00 ppm. [49] The above-determined H (6) coord parameters for 2-benzoyl-py, 2-phenoxy-py and 2-phenylsulfanyl-py coordination compounds (relatively small or even negative) are more uncertain as we have compared the complexes in DMSO-d 6 to the free ligands in CDCl 3 .…”

A Theoretical Assessment of the Thermodynamic Preferences in the Cyclopalladation of Amines

“…[8] However, there are some recent examples of six-membered rings with primary benzyl- [10,30] and ferrocenylamines, [27e] and also with heterocycles. [31] Five-or six-membered rings can be obtained in the cyclopalladation of imines depending on the reaction conditions; [15,32] however, examples with six-membered metallacycles are less common than their five-membered counterparts. [1] In order to test the importance of the ring size we performed calculations with four-, five-, and six-membered rings, both for primary and for tertiary amines (Table 3).…”

Structural and spectroscopic studies of Au(III) and Pd(II) chloride complexes and organometallics with 2-benzylpyridine

“…The former complexation mode occurs in [Au(2bzpy)Cl 3 ] [1] and trans-[Pd(2bzpy) 2 Cl 2 ] [2,3], while the latter in [Au(2bzpy à )Cl 2 ] [1,4] (Scheme 2).…”

“…These compounds are of increasing interest due to their catalytic properties (trans-[Pd(2bzpy) 2 Cl 2 ] in hydrogenation of unsaturated functional groups [5], [Au(2bzpy à )Cl 2 ] in introduction of amine and alkyne substituents into oligosaccharides [6]) and cytotoxicity ([Au(2bzpy à )Cl 2 ] is active against cancer [7] and parasites [8]). [Au(2bzpy à )Cl 2 ] and its [Au(2-(1,1-dimethylbenzyl)pyridine à )Cl 2 ] analogue are also widely used as precursors for preparation of some other compounds with antitumour, antibacterial, antifungal or antiviral properties [9][10][11][12][13][14][15][16][17].…”