Paul D. Higginson

X=Y–ZH systems as potential 1,3-dipoles. Part 56: Cascade 1,3-azaprotio cyclotransfer–cycloaddition reactions between aldoximes and divinyl ketone: the effect of oxime E/Z isomerism on cycloaddition stereoselectivity

Abstract The cascade 1,3-azaprotiocyclotransfer (1,3-APT)-1,3-dipolar-cycloaddition (1,3-DC) reaction between aldoximes and divinyl ketone affords mixtures of exo and endo-isomers of substituted 1-aza-7-oxabicyclo[3.2.1]octan-4-ones, the ratio of which is dependent on the E/Z geometry of the starting oxime and its ability to isomerise under the thermal reaction conditions.

X=Y–ZH systems as potential 1,3-dipoles. Part 57: Cascade 1,3-azaprotio cyclotransfer–cycloaddition reactions between aldoximes and divinyl ketone: remarkable rate enhancement and control of cycloaddition regiochemistry by Lewis acids

Abstract The tandem 1,3-azaprotio cyclotransfer–cycloaddition reaction between aldoximes and divinyl ketone affords the exo-isomers of substituted 1-aza-7-oxabicyclo[3.2.1]octan-4-ones when a substoichiometric amount of hafnium(IV) chloride, zirconium(IV) chloride or aluminium(III) chloride is added.

A novel route to substituted 4-methylene-4,5-dihydroisoxazoles mediated by hafnium(IV) chloride

Heating alkyl vinyl ketones and N-tert-butylarylmethylideneamine N-oxides in the presence of HfCl4 results in the formation of 4-methylene-4,5-dihydroisoxazoles in good yield.

GRIND-based QSPR method to predict the enantiomeric excess in catalysis

damage is being caused to TamR cells. While one explanation may be that the different effect might be caused by a difference in uptake/efflux of drugs, the fact that this effect is peculiar to bleomycin, etoposide and doxorubicin and not other cytotoxics would suggest that the difference between these two cell lines may lie in their ability to detect and repair DSBs and not in their ability to efflux or metabolise them. Further work will establish the DNA repair capacity of these cell lines, as well as their tendency to commit to apoptosis when subjected to certain stresses in order to better understand the underlying differences that cause this phenomenon of double strand break sensitivity.

Tandem 1,3-azaprotiocyclotransfer–cycloaddition reactions between aldoximes and divinyl ketone. Remarkable rate enhancement and control of cycloaddition regiochemistry by hafnium(IV) chloride

The tandem 1,3-azaprotiocyclotransfer–cycloaddition reaction between aldoximes and divinyl ketone affords the exo- isomers of substituted 1-aza-8-oxabicyclo[3.2.1]octan-4-ones when a substoichiometric amount of hafnium(IV) chloride is added.

Tandem 1,3-azaprotio cyclotransfer–cycloaddition reactions between aldoximes and divinyl ketone. The effect of oxime E/Z-isomerism on cycloaddition stereoselectivity

The tandem 1,3-azaprotiocyclotransfer–cycloaddition reaction between aldoximes and divinyl ketone affords mixtures of exo- and endo-isomers of substituted 1-aza-8-oxabicyclo[3.2.1]octan-4-ones, the ratio of which is dependent on the E/Z geometry of the starting oxime and its ability to isomerise under the thermal reaction conditions.