6274-12-0Relevant articles and documents
Synthesis and reactivity of cyclometalated rhenium diaminocarbene complexes
Lu, Kuang-Lieh,Lee, Hsu-Hsiu,Wang, Chen-Mien,Wen, Yuh-Sheng
, p. 593 - 599 (1994)
The diaminocarbene complexes ReBr(CO)4{C(NHR)(NHPh)} (1) react with a secondary amine (Et2NH) to yield the cyclometalated products Re(CO)4{η2-C(NHR)(NHC6H4)} (2a, R = Pri; 2b, R = Pr) via an ortho-metalation process. Treatment of the latter complexes with HBr in CH2Cl2 leads to the opening of the metallacyclic ring to regenerate complex 1. The complex Re(CO)4{η2-C(NHPri)(NHC6H 4)} (2a) reacts with iodine to afford ReI(CO)4{C(NHPri)(NHC6H4I)} (3), which on reaction with secondary amine induces the successive intramolecular activation of a C-H bond to form Re(CO)4{η2-C(NHPri)(NHC6H 3I)} (4). Treatment of 4 with iodine leads to the reopening of the Re-C σ bond to yield the iodo complex ReI(CO)4{C(NHPri)(NHC6H3I 2)} (5). Complex 2a reacts with the Br?nsted acid CH3CO2H or CF3CO2H in CH2Cl2 to give the addition products Re(CO)4(η1-OCOR){C(NHPri)(NHPh)} (6a, R = CH3; 6b, R = CF3). Treatment of 2a with HC≡CCO2H in CH2Cl2 leads to the formation of both the complex Re(CO)4(η1-OCOC≡CH){C(NHPri)(NHPh)} (6c) and the minor species ReCl(CO)4{C(NHPri)(NHPh)} (7). Molecular structures of 3, 6c, and 7 have been determined by X-ray diffraction studies. Crystal data are as follows: 3, Pbcn, a = 7.419(3) A?, b = 16.52(6) A?, c = 32.215(21) A?, V = 3948(14) A?3, Z = 8, R = 8.2%, Rw = 10.2%; 6c, P21/n, a = 9.9905(13) A?, b = 12.7994(14) A?, c = 15.0592(16) A?, β = 96.035(10)°, V = 1915.0(4) A?3, Z = 4, R = 4.1%, Rw = 5.0%; 7, P21/c, a = 15.6532(23) A?, b = 6.4584(14) A?, c = 17.4384(20) A?, β = 107.924(11)°, V = 1677.4(5) A?3, Z = 4, R = 4.4%, Rw = 5.0%.
Palladium-Catalyzed Double-Carbonylation of Alkenyl Halides with Secondary Amines to Give α-Keto Amides
Son, Tae-il,Yanagihara, Hisayoshi,Ozawa, Fumiyuki,Yamamoto, Akio
, p. 1251 - 1258 (2007/10/02)
The double-carbonylation reaction of alkenyl halides with diethylamine in the presence of palladium catalysts has been examined in detail.The reaction gives α-keto amide together with amide, the single carbonylation by-product.The yield of α-keto amide is strongly dependent on the nature of alkenyl halide.Alkenyl bromides or iodides having phenyl group(s) as substituent(s) on the vinyl group are successfully double-carbonylated under appropriate reaction conditions and the corresponding α-keto amides are obtained in good to modest yields together with amides.In contrast, the reactions of alkenyl halides without a phenyl group give amides exclusively.In order to clarify the reason for the substrate-specificity in the reaction, series of alkenyl- and alkenoylpalladium(II) complexes, the presumed intermediates in the catalytic reactions, have been prepared and their reactions with secondary amines, carbon monoxide, and alkenyl halides were examined.The study suggests the operation of three types of processes for amide formation in the catalytic reactions.Possible mechanism for amide as well as α-keto amide formation are discussed.
REACTIONS OF FLUOROALKYL-CONTAINING α-HALOGENATED β-KETOESTERS WITH AMINES
Skryabina, Z. E.,Saloutin, V. I.,Pashkevich, K. I.
, p. 1440 - 1444 (2007/10/02)
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