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Substituted N-[2-(vinyloxy)ethyl]pyrroles, prepared in good yield through an allenic or acetylenic carbanion/isothiocyanate one-pot methodology from 2-(vinyloxy)ethyl isothiocyanate and allyloxyallene, methoxyallene, N,N-dimethyl-2-propyn-1-amine, and 3-methoxy-1-(methylsulfanyl)-1-propyne, are smoothly converted into the corresponding N-vinylpyrroles using t-BuOK/DMSO (room temperature). The reaction proceeds via elimination of vinyl alcohol from the N-[2-(vinyloxy)ethyl] substituent and represents a novel approach to N-vinylpyrroles.

Pressures of as little as 500 bar have been shown to exert a substantial effect upon rates and product ratios of ortho and meta photocycloadditions of ethenes to the benzene ring. In all cases, rates are enhanced by pressure and calculated ‘pseudo-activation volumes’ for both modes of addition appear to be of similar magnitude to those of thermal cycloaddition processes. The pressure-induced discrimination between isomeric meta cycloadducts from the ethyl vinyl ether–benzene system is rationalised in terms of the mechanism involving partial charge separation in the S1 arene and is backed up by calculated molar volumes of the adducts. Similar results are observed for the intramolecular photocycloaddition reactions of arene–ethene non-conjugated bichromophores.

An asymmetric Diels–Alder reaction between 1-phenyl-3,4-dimethylphosphole and ethyl vinyl ketone promoted by a chiral organopalladium complex gives the corresponding keto-substituted phosphine ligands in which the keto group can be stereospecifically located in the endo- or exo-positions of the phosphanorbornene skeleton.

(5R)-3-Methyl-5-phenyl-5H,7H-thiazolo[3,4-c]oxazol-4-ium-1-olate was generated in the presence of a range of dipolarophiles. The intermolecular 1,3-dipolar cycloaddition of this mesoionic species led to the synthesis of chiral 1H-pyrrolo[1,2-c]thiazole derivatives 7a, 7b, 8, 14, 18, 19 and 20. In the reaction with methyl and ethyl vinyl ketone, spiro compounds 9 and 15 were also obtained. The structure of compound 15 was determined by X-ray crystallography.

Reactions of salicyl N-tosylimines with methyl vinyl ketone, ethyl vinyl ketone or phenyl vinyl ketone proceeded smoothly under mild conditions to give the corresponding chromanes or aza-Baylis–Hillman adducts in moderate to excellent yields in the presence of phosphine or nitrogen Lewis base.

Aza-Morita–Baylis–Hillman (aza-MBH) reaction of ethyl (arylimino)acetate with methyl vinyl ketone and ethyl vinyl ketone has been investigated. We found that aza-MBH adducts 1 could be formed in the presence of DABCO (30 mol %) and the corresponding adducts 2 could be obtained in the presence of PPh 3 (30 mol %) in moderate to good yields in acetonitrile under mild conditions, respectively.

Bis(ethylthio)acetals possessing a hydroxy group in the α-position eliminate, upon reaction with copper(I) chloride in dimethylformamide, cleanly and quantitatively one molecule of ethanethiol with the formation of substituted ethyl vinyl sulfides