Both theoretical and experimental investigations are reported for the gas-phase hydrolysis of the radical cation of ketene, H(2)CCO(*+). Density functional theory (DFT) with the B3LYP/6-311++G(d,p) method indicates that a second water molecule is required as a catalyst for the addition of water across the C=O bond in H(2)CCO(*+) by eliminating the activation barrier for the conversion of [H(2)C...

By the reactions of ketimines bearing a pyridyl or a picolyl group on a nitrogen atom of the imine moiety with tosylisocyanate, 4H-pyrido[1,2-a]pyrimidin-4-one derivatives could be obtained in quantitative yields. In these reactions, tosylisocyanate acts as a carbonyl precursor. The pyridyl or picolyl group is a key functional group because it is not only the constituent structure of the 4H-pyr...

A novel and facile route to functionalized mono/bicyclic 2,3-dihydro-4-pyridones has been developed via formal [5C + 1N] annulation of readily available alpha-alkenoyl ketene-(S,S)-acetals with various aliphatic primary amines.

Titanocene and zirconocene ketene acetal derivatives have been prepared by reaction of the respective metallocene dichloride with the lithium enolate of isobutyric acid methyl ester. The crystal structure of (CsH s),Ti(CDOC(OCH 3):C(CH 3) is reported.

We have examined the occurrence of discontinuities in bond-breaking potential energy surfaces given by local correlation methods based on the Pulay-Saebø orbital domain approach. Our analysis focuses on three prototypical dissociating systems: the C-F bond in fluoromethane, the C-C bond in singlet, ketene, and the central C-C bond in propadienone. We find that such discontinuities do not occur ...

Different patterns of photochemical behavior were observed for 4-methoxybenzaldehyde (p-anisaldehyde) isolated in xenon and in argon matrices. Monomers of the compound isolated in solid Xe decarbonylate upon middle ultraviolet irradiation, yielding methoxybenzene (anisole), and CO. On the other hand, p-anisaldehyde isolated in an Ar matrix and subjected to identical irradiation, predominantly i...

Erlotinib (ELT), a tyrosine kinase inhibitor, is widely used for the treatment of nonsmall cell lung cancer in clinic. Unfortunately, severe drug-induced liver injury and other adverse effects occurred during the treatment. Meanwhile, ELT has been reported to be a mechanism-based inactivator of cytochrome P450(CYPs) 3A4 and 3A5. The objectives of this study were to identify ketene intermediate ...

The reaction of dimesityl ketene with P(2)S(5) and pyridine gives 2,4-bis(dimesitylmethylene)-1,3-dithietane (3), 3,6-bis(dimesitylmethylene)-1,2,4,5-tetrathiane (4), 3,5-bis(dimesitylmethylene)-1,2,4-trithiane (5), and dimesityl thioketene 2 as a transient. The structures of 3 and 4 were determined by X-ray crystallography. The dimesitylmethylene moieties in 3 and 4 have a propeller conformati...

Alkenyl alkynyl ketones and ketene silyl acetals (KSAs) undergo regioselective [2+2]-cycloaddition under thermal conditions, triggering domino pericyclic reactions en route to various poly-substituted salicylic acid derivatives.