Woollins' reagent explained

Woollins' reagent is an organic compound containing phosphorus and selenium. Analogous to Lawesson's reagent, it is used mainly as a selenation reagent. It is named after John Derek Woollins.

Preparation

Woollins' reagent is commercially available. It can also be conveniently prepared in the laboratory by heating a mixture of dichlorophenylphosphine and sodium selenide (Na₂Se), (itself prepared from reacting elementary selenium with sodium in liquid ammonia).^[1] An alternative synthesis is the reaction of the pentamer (PPh)₅ (pentaphenylcyclopentaphosphine) with elemental selenium.^[2]

Applications

The main use of Woollins' reagent is the selenation of carbonyl compounds.^[3] For instance, Woollins' reagent will convert a carbonyl into a selenocarbonyl. Additionally, Woollins' reagent has been used to selenonate carboxylic acids, alkenes, alkynes, and nitriles.^[4]

Notes and References

1. Ian P. Gray, Pravat Bhattacharyya, Alexandra Slawin and J. Derek Woollins . 2005 . A New Synthesis of (PhPSe2)2 (Woollins Reagent) and Its Use in the Synthesis of Novel P-Se Heterocycles . . 11 . 21 . 6221–7 . 10.1002/chem.200500291 . 16075451.
2. M. J. Pilkington, Alexandra M. Z. Slawin and J. Derek Woollins . . 1990 . 351–355 . 10.1002/hc.520010502 . 5 . The preparation and characterization of binary phosphorus-selenium rings . 1.
3. Pravat Bhattacharyya . J. Derek Woollins . amp . . 42 . 34 . 2001 . 5949 . 10.1016/S0040-4039(01)01113-3 . Selenocarbonyl synthesis using Woollins reagent. 10023/1776 . free.
4. Guoxiong Hua . J. Derek Woollins . amp . . 48 . 8 . 2009 . 1368–1377 . 10.1002/anie.200800572 . Formation and Reactivity of Phosphorus-Selenium Rings . 19053094.