769968-28-7Relevant articles and documents
Synthesis and reactivity of ortho-palladated arylcarbodiimides and aryl isothiocyanates. Formation of C-palladated quinazolines. Synthesis of 2-aminoquinolines
Vicente, Jose,Abad, Jose-Antonio,Lopez-Serrano, Joaquin,Jones, Peter G.
, p. 4711 - 4722 (2008/10/09)
The iminophosphoranes Ph3P=NC6H3X-2-R-4 (X = I, R = H (1a); X = Br, R = NO2 (1b); X = Br, R = Me (1c)) react with p-tolyl isocyanate and 1a reacts with CS2 to give the carbodiimides ToN=C=NC6H3X-2-R-4 (To = C6H 4Me-4; X = I, R = H (2a); X = Br, R = NO2 (2b); X = Br, R = Me (2c)) and the isothiocyanate S=C=NC6H4I-2 (3), respectively. The compounds 2 and 3 react with Pd(dba)2 ([Pd 2(dba)3]·dba, dba = dibenzylideneacetone) in the presence of the appropriate ligands to give the ortho-palladated arylcarbodiimides [Pd(C6H3N=C=NTo-2-R-5)XL2] (L = PPh3, X = I, R = H (4a); L = PPh3, X = Br, R = NO 2 (4b), Me (4c); L2 = bpy (2,2′-bipyridine), X = I, R = H (5a)) and trans-[Pd(C6H4N=C=S-2)I(PPh 3)2] (6), respectively. Complex 4a reacts with pyridine (py) and Tl(TfO) (TfO = triflate, CF3SO3) and 5a reacts with 4-tert-butylpyridine (tBupy) and Tl(TfO) to give the complexes trans-[Pd(C6H4N=C=NTo-2)(py)(PPh3) 2]TfO (7a) and [Pd(C6H4N=C=NTo-2)( tBupy)(bpy)]TfO (8a), respectively. Complex 4a reacts with XyNC (Xy = 2,6-dimethylphenyl) to give the palladated quinazoline trans-[Pd(ToNqXy)I(CNXy) 2] (ToNqXy = 3-(2,6-dimethylphenyl)-2-[(4-methylphenyl)imino]-2,3- dihydroquinazolin-4-yl (9a)) and with tBuNC to give [Pd(ToNq tBu)I(CNtBu)(PPh3)] (ToNqtBu = 3-tert-butyl-2-[(4-methylphenyl)imino]-2,3-dihydroquinazolin-4-yl (10a′)). Reaction of 10a′ with Tl(TfO) and PPh3 results in the formation of trans-[Pd(ToNHq)(CNtBu)(PPh3)2]TfO (11; ToNHq = 2-[(4-methylphenyl)amino]quinazolin-4-yl). The reaction of R′C=CR′ with 4a, 5a, or 4c gives 2-[(4-methylphenyl)amino]-3,4- R′2-6-R-quinoline (R′ = CO2Me, R = H (12a), Me (12c); R′ = Ph, R = H (12a′)). Some of these reactions require the presence of Tl(TfO). The crystal and molecular structures of 6, 8a·CDCl3, 9a·0.5OEt2, 11, 12a, and 12a′ have been determined.