Oxidative coupling of carbon monoxide and amines catalyzed by cuprous complexes

E.S.R. studies of the oxidative coupling of some bisphenols

Australian Journal of Chemistry ◽

10.1071/ch9750343 ◽

1975 ◽

Vol 28 (2) ◽

pp. 343 ◽

Cited By ~ 10

Author(s):

SM Colegate ◽

FR Hewgill ◽

GB Howie

Keyword(s):

Carbon Monoxide ◽

Alkaline Solution ◽

Unpaired Electron ◽

Oxidative Coupling ◽

Radical Anion ◽

Neutral Solution

E.s.r. spectroscopy and the identification of products show that oxidation of 3,5,3?,5?-tetra-t-butyl-4,4?-dihydroxybenzophenone in neutral solution gives 3,5,3?,5?-tetra-t-butyldipheno-4,4?-quinone. If oxygen is present 2,6-di-t-butyl-p-benzoquinone is also formed. The evolution of carbon monoxide suggests that bis-spirodienones are intermediate in the formation of these products. E.s.r. spectra of radicals produced by oxidation of 3,5,3?,5?-tetra-t-butylbiphenyl-4,4?- dio and 2,6-di-t-butylhydro-quinone have been re-examined. In alkaline solution 3,5,3?,5?-tetra-t-butyl-4,4?-dihydroxybenzo-phenone is oxidized to a radical anion in which the unpaired electron is delocalized over both rings. �� Attempts to detect unsymmetrical bisaryloxy radicals were unsuccessful, 3?,5?-di-t-butyl-4,4?-dihydroxy-3,5-dimethoxybenzophenone forming only the radical derived from the syringoyl portion, and 2,4?- oxydiphenol ether forming only the 4?-oxy radical. Comparison with the observation of both radicals when a mixture of guaiacol and p- methoxyphenol was oxidized suggests that C-O-C coupling in 2,4?- oxydiphenol proceeds by direct radical pairing.

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Oxidative coupling of amines and carbon monoxide catalyzed by palladium complexes. Mono- and double carbonylation reactions promoted by iodine compounds

Canadian Journal of Chemistry ◽

10.1139/v90-238 ◽

1990 ◽

Vol 68 (9) ◽

pp. 1544-1547 ◽

Cited By ~ 38

Author(s):

Ilan Pri-Bar ◽

Howard Alper

Keyword(s):

Carbon Monoxide ◽

Oxidative Coupling ◽

Room Temperature ◽

Palladium Complexes ◽

Secondary Amines ◽

Primary Amines ◽

Palladium Acetate ◽

Principal Product ◽

Iodine Compounds ◽

Primary And Secondary Amines

Iodine is an effective promoter for the carbonylation of primary and secondary amines to ureas using palladium acetate as the catalyst and a base (e.g. K2CO3) in acetonitrile (3 h at 95 °C and 2.7 atm). Oxamides are formed in excellent yields when secondary amines are carbonylated in the presence of iodide ion and oxygen, while primary amines give ureas as the principal product at 95 °C, and oxamide at room temperature. Keywords: oxamides, ureas, double carbonylation, amines.

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