AbstractThe cadmium(II) chloride-catalyzed dehydrative C−P cross-coupling reaction of propargyl alcohols with diarylphosphine oxides is reported. Several propargyl alcohols including those bearing the sterically demanding tert-butyl group at the triple bond terminus can be used as good substrates in the reaction to produce the corresponding allenylphosphine oxides in good to high yields in acetonitrile at 100 °C. The reaction can also be easily scaled up to a gram-scale synthesis. A mechanism study indicates that the reaction may proceed through a process of propargylic substitution to generate phosphonite intermediates followed by [2,3] sigmatropic rearrangement to produce the allenyl products, rather than through a common allenylative substitution resulting from P-nucleophilicity.

A novel Cu-catalysed substitution reaction of propargyl acetates with P(O)H compounds is developed to afford allenylphosphoryl compounds via C–P bond coupling in high yields under mild conditions. A plausible mechanism involving the nucleophilic interception of the Cu-allenylidene intermediates is proposed.

A novel Pd-catalyzed tandem reaction involving hydroalkynylation, isomerization, Diels–Alder cycloaddition and aromatization reaction to produce phthalan derivatives in moderate yields is reported. The reaction is atom economical and occurs in a highly ordered fashion. The reaction mechanism is discussed.A novel Pd-catalyzed tandem reaction involving hydroalkynylation, isomerization, Diels–Alder cycloaddition and aromatization reaction to produce phthalan derivatives in moderate yields is reported. The reaction is atom economical and occurs in a highly ordered fashion and the reaction mechanism is also discussed.

An atom-economic tandem Pd(II)-catalyzed hydroalkynylation, alkyne-allene isomerization, and Diels–Alder cycloaddition is reported. The reaction employs readily available starting substrates, proceeds in a highly ordered fashion, features high regio- and stereoselectivity, and tolerates a wide range of functionality and structural motifs, thus offering an attractive strategy for producing new molecular complexity and diversity from easily available starting materials. A mechanistic study with density functional theoretical calculations was conducted to rationalize the observed stereoselectivity.

A novel Cu-catalysed substitution reaction of propargyl acetates with P(O)H compounds is developed to afford allenylphosphoryl compounds via C–P bond coupling in high yields under mild conditions. A plausible mechanism involving the nucleophilic interception of the Cu-allenylidene intermediates is proposed.

A novel CuI-catalyzed cross-coupling of propargyl epoxides with P(O)H compounds is disclosed. The reaction proceeded efficiently under mild conditions to give 4-phosphoryl 2,3-allenols in good to high yields with excellent selectivity. The utility of the products was demonstrated and a plausible mechanism was also proposed.