Synthesis of organic phosphorus compounds from elemental phosphorus

Photoinduced Reactivity of Red Phosphorus and Ethanol at High Pressure

“…The syntheses in general consist of a two-step process where the direct chlorination of P 4 using chlorine is followed by the phosphorylation of the organic substrate with phosphorus chloride. 20 However, the use of chlorine makes this method environmentally unfriendly stimulating the search for alternative synthetic approaches. Catalytic processes directly combining white phosphorus and organic molecules through suitable transition metal complexes have been proposed as viable methods for controlled white phosphorus alkoxydation.…”

“…These chemicals, as well as inorganic phosphates, are present in many products of widespread use such as fertilizers, insecticides, detergents, and pharmaceuticals, but for their syntheses, the most reactive allotrope, white phosphorus P 4 , is preferred as the starting material. The syntheses in general consist of a two-step process where the direct chlorination of P 4 using chlorine is followed by the phosphorylation of the organic substrate with phosphorus chloride . However, the use of chlorine makes this method environmentally unfriendly stimulating the search for alternative synthetic approaches.…”

Products and Mechanisms in the Oxidation of Phosphorus by Sulfur at Low Temperature

“…Bimolecular, 2-electron reactions between P 4 and S 8 are expected to be very slow because neither is a good nucleophile. , One-electron transfer from sulfur to phosphorus would generate, after radical pair collapse, the same intermediate discussed below and therefore is mechanistically impossible to distinguish. Initiation of this oxidation reaction by the formation of a high-energy S n species (S 8 diradical, thionsulfoxide, or S 6 ) is therefore a logical starting point.…”

“…Among the unique alternatives discussed above, the initial formation of • S−S 6 −S • from S 8 is most consistent with both the properties of the reactants and the experiments performed. The fact that elemental sulfur easily forms diradicals and the known sensitivity of phosphorus toward formation of bonds with radicals ,, support the choice of building a model of this reaction based on an initial addition of 19 to P 4 . The next question to be answered is whether the formation of 20 and 21 can lead to the observed products.…”

“…This choice was made in order to make use of the observation that compounds of low S:P 4 ratio are not made most rapidly. There is good precedent from the chemistry of elemental sulfur for the intramolecular cyclization to form small rings and small fragments from larger diradical chains. ,, Intermediates such as 22 could opt for S−S bond formation with a sulfur in the chain other than the S-radical terminus, forming instead a species like 21 , only with fewer sulfur atoms in the chain, and a S n fragment. That this is not a major path is supported by the fact that P 4 S 3 and α-P 4 S 5 are not among the most rapidly formed products.…”