Teruyuki Kondo

Ruthenium complex-catalyzed allylic alkylation of carbonucleophiles with allylic carbonates

Abstract Allylic carbonates except for allyl methyl carbonate reacted with carbonucleophiles such as ethyl acetoacetate in the presence of a catalytic amount of Ru(cod)(cot) [cod = cycloocta-1,5-diene, cot = cycloocta-1,3,5-triene] in N -methylpiperidine at 80°C to give the corresponding monoallylated carbonucleophiles in high yields with high regioselectivity. The regioselectivity was quite different from that in the palladium-catalyzed reactions. The allylation of carbonucleophiles using allyl methyl carbonate selectively gave the diallylated carbonucleophiles in high yields.

Ruthenium-catalyzed intramolecular hydroamination of aminoalkynes

Low-valent ruthenium complexes with a p-acidic ligand, such as Ru(h 6 -cot)(dmfm)2 [cot 1,3,5-cyclooctatriene, dmfm dimethyl fumarate] and Ru3(CO)12, showed high catalytic activity for the intramolecular hydroamination of aminoalkynes. The reaction is highly regioselective, in which a nitrogen atom is selectively attached to an internal carbon of alkynes to give five-, six-, and seven-membered nitrogen heterocycles as well as indoles in good to high yields.

Palladium complex-catalyzed intermolecular reductive N-heterocyclization: novel synthesis of quinazoline derivatives from 2-nitrobenzaldehyde or 2-nitrophenyl ketones with formamide

Abstract A combination of the palladium complex PdCl2(PPh3)2 with MoCl5 shows a high catalytic activity for the intermolecular reductive N-heterocyclization of 2-nitrobenzaldehyde or 2-nitrophenyl ketones with formamide to give the corresponding quinazoline derivatives in moderate yields. For example, in the reaction of 2-nitrobenzaldehyde with formamide, quinazoline was obtained in 46% yield. We assume that the present reaction proceeds via an active nitrene intermediate which would be generated by selective deoxygenation of nitro group by carbon monoxide.

Dodecacarbonyltriruthenium catalysed carbonylation of amines and hydroamidation of olefins

Abstract Dodecacarbonyltriruthenium (Ru 3 (CO) 12 ) is an effective homogeneous catalyst precursor for the carbonylation of amines and hydroamidation of olefins under a carbon monoxide pressure of 40 kg cm −2 at 120–180°C. By the carbonylation of benzylamine, N -benzylformamide was obtained in 77% yield. 1-Octene was hydroamidated with benzylamine to N -benzylnonanamide in 67% yield (the selectivity to its linear isomer was 81%). These reactions appear to include ruthenium carbamoyl complex as the common key intermediate.

Dodecacarbonyltriruthenium catalyzed one-to-one addition of N-substituted formamide to olefins

Abstract Dodecacarbonyltriruthenium (Ru 3 (CO) 12 ) showed high catalytic activity for the first one-to-one addition of N -substituted formamides to both terminal and internal olefins at 180-200°C under a carbon monoxide pressure of 20 kg cm −2 . The addition of N -metylformamide to cyclopentene afforded N -methylcyclopentanecarboxamide in 90% yield.

Ruthenium complex catalyzed intermolecular hydroacylation of olefins

Abstract Dodecacarbonyltriruthenium (RU 3 (CO) 12 ) and (η 4 -1,5-cyclooctadiene)(η 6 -1,3,5cyclooctatriene) ruthenium (Ru(COD)(COT)) catalyzed the hydroacylation of olefins with aldehydes at 180–200 °C for 48 h under 20 kgcm −2 of carbon monoxide to give unsymmetric ketones in good yields.

Photochemical carbonylation of alkyl iodides in the presence of various metal carbonyls

Various transition metal complexes including group VII and VIII metal carbonyls are highly active catalyst precursors for the photochemical carbonylation of organic iodides at room temperature under an atmospheric pressure of carbon monoxide. Primary, secondary and tertiary alkyl iodides which have β-hydrogens on sp3-carbons were smoothly carbonylated by this catalyst system without β-hydride elimination to give the corresponding esters in yields of 63 - 88 %.

Ru3(CO)12-(CH3)3NO·2H2O-catalyzed hydroesterification of olefins with alkyl formates

Abstract The Ru3(CO)12-(CH3)3NO·2H2O catalyst system shows high catalytic activity for the hydroesterification of olefins, especially cyclohexene, with alkyl formates at 200 °C for 6 h under 20 kg cm−2 of carbon monoxide. The treatment of cyclohexene with benzyl formate afforded benzyl cyclohexane-carboxylate in 68% yield.

Photo-, electro-, and thermal carbonylation of alkyl iodides in the presence of group 7 and 8–10 metal carbonyl catalysts

Abstract Various transition-metal complexes including Group 7 and 8–10 metal carbonyls are highly active catalyst precursors for the photochemical carbonylation of alkyl iodides having β-hydrogens on saturated sp 3 -carbons at room temperature under 1 atm of carbon monoxide. Primary, secondary and tertiary alkyl iodides are smoothly carbonylated by this catalyst system without β-hydride elimination (dehydrohalogenation) to give the corresponding esters or amides in high yields. In employment of Mn 2 (CO) 10 as a catalyst, electrochemical carbonylation of alkyl iodides also occurred via generation of an anionic manganese carbonyl intermediate. Actually, anionic manganese carbonyl complexes (pentacarbonylmanganates) showed high catalytic activity for thermal carbonylation of alkyl iodides at room temperature under 1 atm of carbon monoxide without photo-irradiation and electrolysis. Mechanistic studies were performed with kinetics and ESR and it was suggested that the present photo-, electro- and thermal carbonylation would involve a non-chain radical mechanism.

Ruthenium complex-catalyzed selective syntheses of 3,5-dienoic acid derivatives by coupling of 1,3-dienes or allylic carbonates with acrylic compounds

Abstract Ru(cod)(cot) catalyzes highly selective codimerization of 1,3-dienes with acrylic compounds and first linear coupling reaction of allylic carbonates with the acrylic amide to give 3,5-dienoic acid derivatives; cod = cycloocta-1,5-diene, cot = cycloocta-1,3,5-triene.