This tutorial review aims at presenting recent contributions dealing with organic chemistry of organophosphorus radicals. The first part briefly lays out the physical organic background of such intermediates. In a second part the use of organophosphorus radicals possessing a P–H bond that can undergo homolytic cleavage as alternative mediators is detailed. The third part is focused on radical additions of phosphorus-centered radicals to unsaturated compounds, an old reaction that is being rejuvenated. Lastly, radical eliminations of phosphorus-centered radical are introduced in the fourth part. Most of the latter are relatively novel reactions, and have never been reviewed previously.

Recent advances in the use of phosphorus-centered radicals in organic chemistry

A novel and practical approach to monosubstituted phosphinic acid (alkylphosphonous acid) derivatives from hypophosphite salts or esters is described. Phosphorus-centered radical formation is initi...

Triethylborane-Initiated Room Temperature Radical Addition of Hypophosphites to Olefins: Synthesis of Monosubstituted Phosphinic Acids and Esters

Formation of five- and six-membered heterocyclic rings under radical cyclisation conditions

Diethylphosphine oxide (DEPO): high-yielding and facile preparation of indolones in water

The use of free radical initiators bearing metal–metal, metal–hydrogen and non-metal–hydrogen bonds in synthesis

Biowaiver monograph for immediate-release solid oral dosage forms: fluconazole.

Efficient large-scale radical deoxygenation in alcoholic solvents using sodium hypophosphite and a phase-transfer agent: application to erythromycins.

The African Union’s Pharmaceutical Manufacturing Plan for Africa was established to develop the African pharmaceutical industry, a sector with considerable promise for reducing the burden of disease in Africa. With a projected value of over US$40 billion by the next decade, the sector also has the potential to promote economic growth. Additionally, as a technology-based industry it is positioned to advance Africa’s aspiration to transition into a knowledge-based economy. Considerable progress has been made since the development of a business plan for implementing the Pharmaceutical Manufacturing Plan for Africa. This includes initiatives to harmonize medicine regulation on the continent, address human capacity and skills shortages, and to promote cooperation and advocacy in the industry. The promise of the sector has also galvanized countries and regions with manufacturing capacity to harness support for its development. The rate-limiting step in this quest is making funding available to build the needed capacity in infrastructure and in Good Manufacturing Practices, as stipulated by the Pharmaceutical Manufacturing Plan for Africa. A proposed new initiative, the Fund for African Pharmaceutical Development, currently under consideration by the African Union, may provide the boost needed to overcome this final hurdle.

Pharmaceutical Sector Development in Africa: Progress to Date

A process for the preparation of 4"-deoxyerythromycins, having the formula: ##STR1## wherein R is H or OH, R 1 is H or loweralkyl, and R 2 is H or CH 3 by treatment of the starting material, 2'-O-acetyl-4"-imidazolylthiocarbamoyl-erythromycin, with a hypophosphite reagent, in a water-miscible protic solvent optionally comprising a phase transfer agent. In a preferred embodiment, the water-miscible solvent is an alcohol and the starting material is reacted with sodium hypophosphite, ACVA and tetra-n-butylammonium hydroxide.

Hypophosphite deoxygenation reactions in the synthesis of erythromycin derivatives

A process for the preparation of 4''-deoxyerythromycins, having formula (I), wherein R is H or OH, Rp is H or acetyl, and R1 is H or loweralkyl; by treatment of the 2'-O-acetyl-4''-imidazolylthionocarbonyl-erythromycin starting material with the radical initiator 4,4'-azobis-(4-cyanovaleric acid), H?3?PO2 and an organic base in a water-miscible solvent other than an alcohol, and optionally eliminating the 2'-O-acetyl group. In a preferred embodiment, the water-miscible solvent is an alcohol and the deoxygenation and deacetylation is carried out in one step.

Alexandra E. Graham

Papers

Biowaiver monograph for immediate-release solid oral dosage forms: fluconazole.

Efficient large-scale radical deoxygenation in alcoholic solvents using sodium hypophosphite and a phase-transfer agent: application to erythromycins.

Pharmaceutical Sector Development in Africa: Progress to Date

Hypophosphite deoxygenation reactions in the synthesis of erythromycin derivatives

Process for preparation of 4-deoxyerythromycins a and b