A revised pathway for the catalytic Staudinger amidation reaction is presented that involves the intervention of in situ-generated silyl esters as the species responsible for amidation.

We report a catalytic reductive alkylation reaction of primary or secondary amines with carboxylic acids. The two-phase process involves silane mediated direct amidation followed by catalytic reduction.

We report a synthesis method for the construction of quaternary aryl phoshonium salts at ambient temperature. The regiospecific reaction involves the coupling of phosphines with aryl radicals derived from diaryliodonium salts under photoredox conditions.

The development of the first redox-free protocol for the Mitsunobu reaction is described. This has been achieved by exploiting triphenylphosphine oxide – the unwanted by-product in the conventional Mitsunobu reaction – as the precursor to the active P(V) coupling reagent. Multinuclear NMR studies are consistent with hydroxyl activation via an alkoxyphosphonium salt.

The conversion of a commercially available polystyrene supported phosphine oxide into synthetically useful polymeric halophosphonium salts using oxalyl chloride/bromide takes place at room temperature in 5 min and generates only CO and CO2 as by-products. The polymeric halophosphonium salts so obtained are useful reagents for Appel halogenations and other dehydrative coupling reactions. This gives rise to a simple three-step synthesis cycle for Appel and related reactions using a commercially available polymeric phosphine oxide with very simple purification and no phosphorus waste.

A synthesis of the core ring structure of the fargenin/fargenone family of natural products is presented. The general strategy is based upon biosynthetic speculation and exploits a cascade reaction, which transforms a spirocyclic dienone into the core ring system via a deprotonation–oxy-Michael–Wittig olefination sequence. This study represents the first synthesis work towards this family of natural products.

A concise and protecting group free synthesis of the naturally occurring neolignan 4′-O-methyl honokiol is developed. The key biaryl bond is constructed by 1,2-addition of an aryl Grignard reagent to a dienone followed by rearrangement.

Catalytic phosphorus(V)-mediated chlorination and bromination reactions of alcohols have been developed. The new reactions constitute a catalytic version of the classical Appel halogenation reaction. In these new reactions oxalyl chloride is used as a consumable stoichiometric reagent to generate the halophosphonium salts responsible for halogenation from catalytic phosphine oxides. Thus, phosphine oxides have been transformed from stoichiometric waste products into catalysts and a new concept for catalytic phosphorus-based activation and nucleophilic substitution of alcohols has been validated. The present study has focused on a full exploration of the scope and limitations of phosphine oxide catalyzed chlorination reactions as well as the development of the analogous bromination reactions. Further mechanistic studies, including density functional theory calculations on proposed intermediates of the catalytic cycle, are consistent with a catalytic cycle involving halo- and alkoxyphosphonium salts as intermediates.

A stereospecific triphenylphosphine oxide-catalyzed 1,2-dichlorination reaction of epoxides has been developed. The reaction is effective for a range of terminal and internal epoxides. In contrast to the classical Appel-type dichlorination of epoxides, oxalyl chloride is used as a stoichiometric reagent to generate the chlorophosphonium salt responsible for dichlorination from catalytic triphenylphosphine oxide.

A phosphine oxide-catalysed chlorination reaction of primary and secondary alcohols has been developed. This process represents the first triphenylphosphine oxide-catalysed alcohol chlorination under Appel conditions.

We report a synthesis method for the construction of quaternary aryl phoshonium salts at ambient temperature. The regiospecific reaction involves the coupling of phosphines with aryl radicals derived from diaryliodonium salts under photoredox conditions.

We report a 12-step catalytic enantioselective formal synthesis of malhamensilipin A (3) and diastereoisomeric analogues from (E)-2-undecenal. The convergent synthesis relied upon iterative epoxidation and phosphorus(V)-mediated deoxydichlorination reactions as well a titanium-mediated epoxide-opening to construct the C11–C16 stereohexad. The latter transformation occurred with very high levels of stereoretention regardless of the C13 configuration of the parent epoxide, implicating anchimeric assistance of either the γ- or δ-chlorine atoms, and the formation of chloretanium or chlorolanium ions, respectively. A computational analysis of the chloronium ion intermediates provided support for the involvement of chlorolanium ions, whereas the potential chloretanium ions were found to be less likely intermediates on the basis of their greater carbocationic character.

A synthesis of the core ring structure of the fargenin/fargenone family of natural products is presented. The general strategy is based upon biosynthetic speculation and exploits a cascade reaction, which transforms a spirocyclic dienone into the core ring system via a deprotonation–oxy-Michael–Wittig olefination sequence. This study represents the first synthesis work towards this family of natural products.

The development of the first redox-free protocol for the Mitsunobu reaction is described. This has been achieved by exploiting triphenylphosphine oxide – the unwanted by-product in the conventional Mitsunobu reaction – as the precursor to the active P(V) coupling reagent. Multinuclear NMR studies are consistent with hydroxyl activation via an alkoxyphosphonium salt.

A phosphine oxide-catalysed chlorination reaction of primary and secondary alcohols has been developed. This process represents the first triphenylphosphine oxide-catalysed alcohol chlorination under Appel conditions.

We report a catalytic reductive alkylation reaction of primary or secondary amines with carboxylic acids. The two-phase process involves silane mediated direct amidation followed by catalytic reduction.

A revised pathway for the catalytic Staudinger amidation reaction is presented that involves the intervention of in situ-generated silyl esters as the species responsible for amidation.