Harold W. Heine

The Reactions of o-Quinone Monoimides with Some Thiophenes and Furans

o-Quinone monoimides undergo inverse electron demand Diels-Alder reactions with thiophene, 2-alkylated thiophenes, 2-and 2,5-alkylated furans and benzofurans. 2,5-Dimethylthiophenes and 2-methylbenzo[b]thiophene, on the other hand interact with o-quinone monoimides to yield ethers, products arising from hydride abstractions from the methyl groups by the imido nitrogen of 6

Reactions of some conjugated dienes with an o-quinone monoimide

Abstract The reactions of N-(2,4-dichloro-6-oxo-2,4-cyclohexadien-1-ylidene)-4-nitrobenzamide ( 1 ) with various conjugated dienes have been studied. The heterodiene system of 1 reacts with one of the double bonds of E-1, 3-pentadiene, E,E-2,4-hexadiene, E,E-1,4-diphenyl-1,3-butadiene, E,E-2,4-hexadienal, ethyl sorbate, 1-methoxy-1,3-butadiene, cyclopentadiene, 1,2,3,4-tetra-phenylcyclopentadiene in an inverse electron-demand Diels-Alder reaction to give derivatives of 2,3-dihydro-1,4-benzoxazines. In contrast to the above dienes 1,3-butadiene adds across the N-acylimino group of 1 to give the spiro adduct 2b .

Unusual cycloaddition of some 1-acyl indoles to an o-quinone monoimide

1-Acyl indoles act as dienophilic components of a [4+2]-cycloaddition when treated with an o-quinone monoimide: an X-ray crystal structure determination established the structure of one of the adducts.

Geometrical isomerism arising from oxidative addition of an o-quinone monoimide to IrCl(CO)(PPh3)2

Abstract A suspension of the o -quinone monoimide 1,2-N(C(O)-4-C 6 H 4 NO 2 )O-2,4-C 6 H 4 Cl 2 and IrCl(CO)PPh 3 ) 2 in CH 2 Cl 2 was stirred for 3 days at room temperature. After careful chromatography two compounds were isolated, both with the empirical formula Ir(1,2-N(C(O)-4C 6 H 4 NO 2 )O-2,4-C 6 H 2 Cl 2 )Cl(CO)(PPh 3 ) 2 . These were shown by 1 H, 13 C and 31 P NMR and IR spectroscopy to be two of the twelve geometrical isomers possible for this complex. X-Ray crystallography confirmed these structures and showed that one isomer has cis and the other trans triphenylphosphine ligands.