Recent Breakthroughs in P₄ Chemistry: Towards Practical, Direct Transformations into P₁ Compounds

Abstract

For several decades, academic researchers have been intensively studying the chemistry of white phosphorus (P 4 ) in the hope of developing direct methods for its transformation into useful P-containing products. This would bypass the hazardous, multistep procedures currently relied on by industry. However, while academically interesting P 4 activation reactions have become well established, their elaboration into useful, general synthetic procedures has remained out of reach. Very recently, however, a series of independent reports has begun to change this state of affairs. Each shows how relatively simple and practical synthetic methods can be used to access academically or industrially relevant P 1 compounds from P 4 directly, in "one pot" or even in a catalytic fashion. These reports mark a step change in the field of P 4 chemistry, and suggest its possible transition from an area of largely academic interest to one with the promise of true synthetic relevance.

Photochemical Benzylation of White Phosphorus

“…White phosphorus (P 4 ) acts as a starting industrial material for the large-scale preparation of organophosphorus compounds (OPCs) via a classical P 4 → PCl 3 → OPCs route. From the economic and waste-disposal viewpoints, the direct functionalization of P 4 without chlorination to construct P–C bonds is of great significance and is becoming a hot area . There are some methods to achieve P 4 activation, − but the strategy for the direct construction of P–C bonds is still very limited. − Currently, many recent studies have witnessed the rapid development of photochemistry in the field of synthetic organic chemistry; however, photochemistry is rarely used in the synthesis of OPCs through the direct formation of P–C bonds from P 4 .…”

Taming PH3: State of the Art and Future Directions in Synthesis

“…PH 3 is the next downstream output from elemental phosphorus, which comes directly from industrial large-scale processing of phosphate rock . Numerous reviews on functionalization of P 4 exist, but the tetra-nuclear nature of this feedstock means that controlled, direct, or catalytic functionalization of P 4 into, for example, 4PR 3 is not well-documented. , Instead, conversion of P 4 into PH 3 or PCl 3 and onward reaction to form organophosphines is the more traditional pathway. Onward reactions of PCl 3 with organic substrates to prepare P–C­( sp 3 ) bonds are well documented, but wasteful in terms of atom economy.…”

Three-component coupling reaction of white phosphorus, alcohols and diaryl disulfides: a chlorine-free avenue for accessing phosphorothioates

“…Hence, green and efficient routes for the direct conversion of P 4 into value-added organophosphorus compounds (OPCs) are highly valuable and significant from both economic and environmental perspectives. 5–8…”