Synthesis and Reactivity of Ortho-Palladated Arylureas. Synthesis and Catalytic Activity of a C,N,C Pincer Complex. Stoichiometric Syntheses of Some N-Heterocycles
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- 作者：José ; Vicente ; José ; -Antonio Abad ; Joaquí ; n Ló ; pez-Serrano ; Peter G. Jones ; Carmen Ná ; jera ; and Luis Botella-Segura
- 刊名：Organometallics
- 出版年：2005
- 出版时间：October 10, 2005
- 年：2005
- 卷：24
- 期：21
- 页码：5044 - 5057
- 全文大小：278K
- 年卷期：v.24,no.21(October 10, 2005)
- ISSN：1520-6041
文摘
1-(2-Iodophenyl)-3-p-tolylurea (1) reacts with Pd(dba)2 ([Pd2(dba)3]·dba; dba = dibenzylideneacetone) in the presence of the appropriate ligands to give the ortho-palladated arylureas[Pd{C6H4NHC(O)NHTo-2}IL2] (To = C6H4Me-4; L2 = tbubpy (4,4'-di-tert-butyl-2,2'-bipyridine)(2a), tmeda (N,N,N',N'-tetramethylethylenediamine) (2b); L = PPh3 (2c)). Reaction of 2bwith Tl(TfO) (TfO = triflate, CF3SO3) results in the formation of cyclopalladated [Pd{
2C,O-C6H4NHC(O)NHTo-2}(tmeda)]OTf (3b). The latter reacts with PPh3 to yield [Pd{C6H4NHC(O)NHTo-2}(tmeda)(PPh3)]OTf (4b). Treatment of 2b with CO gives the corresponding acylderivative [Pd{C(O)C6H4NHC(O)NHTo-2}I(tmeda)] (5b). If Tl(TfO) is added after thebubbling of CO, the C,N coupling product 3-p-tolyl-1H-quinazoline-2,4-dione (6) is formed.Complex 5b reacts with XyNC (Xy = 2,6-dimethylphenyl) to yield trans-[Pd{C(O)C6H4NHC(O)NHTo-2}I(CNXy)2] (7). Both 5b and 7 decompose in solution to give 6. Complex 2b reactswith isocyanides to give the iminoacyl derivatives trans-[Pd{C(=NR)C6H4NHC(O)NHTo-2}I(CNR)2] (R = Xy (8x), tBu (8t)). The complex 8x gives the C,N coupling product4-(xylylimino)-3-p-tolyl-3,4-dihydro-1H-quinazolin-2-one (9) after treatment with TlOTf. 8xalso reacts with bases (K2CO3 and Tl2CO3) to yield the iminoacyl amido carbene C,N,C pincerpalladium complex [Pd{3C,N,C-C(=NXy)C6H4NC(O)NToC(NHXy)-2}(CNXy)] (10); thiscomplex is an active precatalyst in Heck and Suzuki reactions. The reaction of 2b with R'C
CR' ' and TlOTf gives [Pd{2C,N-CR'=CR' 'C6H4NHC(O)NHTo-2}(tmeda)]OTf (R' = R' ' = Et(11be), CO2Me (11bm), Ph (11bp); R' = Ph, R' ' = CO2Me (11bq)). These complexesdecompose in solution, and in the case of 11bp, 2,3-diphenylindole-1-carboxylic acidp-tolylamide (12p) was isolated. 11bq reacts with PPh3 to give 3-phenyl-1H-indole-2-carboxylic acid methyl ester (13q). 11bp and 11bq decompose in the presence of CO to yield3,4-diphenyl-2-quinolone (14po) and 2-oxo-4-phenyl-1,2-dihydroquinoline-3-carboxylic acidmethyl ester (14qo), respectively. Similarly, when 11bq is reacted with XyNC, the C,Ncoupling compound 2-xylyl-4-phenyl-1,2-dihydroquinoline-3-carboxylic acid methyl ester(14qnx) is formed. The crystal and molecular structures of 3b, 10·0.5CDCl3, 11bp·OEt2,11bq, and 14po have been determined.
2C,O-C6H4NHC(O)NHTo-2}(tmeda)]OTf (3b). The latter reacts with PPh3 to yield [Pd{C6H4NHC(O)NHTo-2}(tmeda)(PPh3)]OTf (4b). Treatment of 2b with CO gives the corresponding acylderivative [Pd{C(O)C6H4NHC(O)NHTo-2}I(tmeda)] (5b). If Tl(TfO) is added after thebubbling of CO, the C,N coupling product 3-p-tolyl-1H-quinazoline-2,4-dione (6) is formed.Complex 5b reacts with XyNC (Xy = 2,6-dimethylphenyl) to yield trans-[Pd{C(O)C6H4NHC(O)NHTo-2}I(CNXy)2] (7). Both 5b and 7 decompose in solution to give 6. Complex 2b reactswith isocyanides to give the iminoacyl derivatives trans-[Pd{C(=NR)C6H4NHC(O)NHTo-2}I(CNR)2] (R = Xy (8x), tBu (8t)). The complex 8x gives the C,N coupling product4-(xylylimino)-3-p-tolyl-3,4-dihydro-1H-quinazolin-2-one (9) after treatment with TlOTf. 8xalso reacts with bases (K2CO3 and Tl2CO3) to yield the iminoacyl amido carbene C,N,C pincerpalladium complex [Pd{3C,N,C-C(=NXy)C6H4NC(O)NToC(NHXy)-2}(CNXy)] (10); thiscomplex is an active precatalyst in Heck and Suzuki reactions. The reaction of 2b with R'CCR' ' and TlOTf gives [Pd{2C,N-CR'=CR' 'C6H4NHC(O)NHTo-2}(tmeda)]OTf (R' = R' ' = Et(11be), CO2Me (11bm), Ph (11bp); R' = Ph, R' ' = CO2Me (11bq)). These complexesdecompose in solution, and in the case of 11bp, 2,3-diphenylindole-1-carboxylic acidp-tolylamide (12p) was isolated. 11bq reacts with PPh3 to give 3-phenyl-1H-indole-2-carboxylic acid methyl ester (13q). 11bp and 11bq decompose in the presence of CO to yield3,4-diphenyl-2-quinolone (14po) and 2-oxo-4-phenyl-1,2-dihydroquinoline-3-carboxylic acidmethyl ester (14qo), respectively. Similarly, when 11bq is reacted with XyNC, the C,Ncoupling compound 2-xylyl-4-phenyl-1,2-dihydroquinoline-3-carboxylic acid methyl ester(14qnx) is formed. The crystal and molecular structures of 3b, 10·0.5CDCl3, 11bp·OEt2,11bq, and 14po have been determined.