Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Media: XI.1 Phosphorylation of 4-Methoxybenzyl Chloride with Elemental Phosphorus and Phosphine

4-Methoxybenzyl chloride reacts with elemental (red or white) phosphorus under the conditions of phase-transfer catalysis (concentrated aqueous KOH, dioxane, benzyltriethylammonium chloride, 85-90°C, argon) to give as major product tris(4-methoxybenzyl)phosphine oxide in up to 45% yield. With white phosphorus at lower (70°C) temperature this reaction yields mainly bis(4-methoxybenzyl)phosphine oxide. Phosphine reacts with 4-methoxybenzyl chloride in superbasic KOH-DMSO suspension, and under definite conditions bis(4-methoxybenzyl)phosphine oxide is predominantly formed.