Nucleophilic Attack of Amides onto Coordinated Ethylene in Platinum Complexes Supported by a Chelating Pyridyl-Pyrrolide Ligand: Azaplatinacyclobutane and Vinylamine Complexes

作者：McBee Jennifer L; Tilley T Don^*

来源：Organometallics, 2010, 29(1): 184-192.

DOI：10.1021/om900569b

The platinum ethylene complexes (PyPyr)Pt(C(2)H(4))Cl (1) and (PyPyr)Pt(C(2)H(4))OTf (4) (PyPyr = 3,5-diphenyl-2-(2-pyidyl)pyrrolide) were treated with 1 equiv of LiN(SiMe(3))(2), LiN(i)Pr(2), and LiNH-(o-xylyl) to produce the platinum complexes (PyPyr)PtH[eta(2)-CH(2)=CHN(SiMe(3))(2)] (5), (PyPyr)Pt[k(2) C,N-(CH(2)CH(2)N(i)Pr(2))] (6), and (PyPyr)Pt{k(2)C,N-[CH(2)CH(2)NH(o-xylyl)]} (7), respectively. X-ray crystallography reveals that 7 adopts a square-planar geometry at the platinum center and the azaplatinacyclobutane ring displays I puckering of the beta-carbon out of planarity by 0.270 angstrom. Thermolysis of 5 and 7 at 60 degrees C for 16 h releases the vinylamines (CH(2)=CH)N(SiMe(3))(2) and (CH(2)=CH)NH(o-xylyl), respectively. Heating 5 and 7 under 1 atm of H(2) at 60 degrees C releases the ethylamines EtN(SiMe(3))(2) and EtNH(o-xyly]), respectively. Addition Of PiPr(3) to 7 produces (PyPyr)Pt(P(i)Pr(3))[CH(2)CH(2)NH(o-xylyl)] (8) in 95% yield, while additions of I equiv of a Lewis base (L) to I result in displacement of ethylene to give (PyPyr)Pt(L)Cl (L = NEt(3) (9), NH(2)Ph (10), P(i)Pr(3) (11)). The amido complex (PyPyr)Pt(P(i)Pr(3))[NH(o-xylyl)] (12) results from treatment of 11 with LiNH(o-xylyl), and 12 does not undergo ethylene insertion into the Pt-N bond Linder I atm of C(2)H(4) at 120 degrees C over 3 days. Addition of 1 equiv of LiNH(o-xylyl) to (PyPyr)Pt(SMe(2))Cl (2) produces the mu-amido-bridged dimer [(PyPyr)Pt(mu-NH(o-xylxyl))](2) (13), and treatment of 13 with 2 equiv Of (i)Pr(3)P produces 12. These reactivity Studies are consistent with a mechanism for the formation of 5-7 involving nucleophilic attack of ail amide onto coordinated olefin.

• 出版日期2010-1-11