Grignard reagents, with phosphorus

The reaction of Grignard reagents with phosphorus trichloride usually proceeds all the way to the tertiary phosphine, R3P. Stepwise alkylation is rarely observed. Examples of the latter include the formation of small amounts of the monochloro-phosphines, (n-C8 Hi7 )2 PCI2 and (C6Hn)2 PCI,3 in the reaction of the appropriate Grignard reagents with phosphorus trichloride. In... 

Apparently a steric factor prevents formation of tri- er -butylphos-phine in the classic reaction. A 3 1 ratio of the er -butyl Grignard reagent with phosphorus trichloride gave after oxidation di- er -butyl-phosphinic acid in low yield (6%) (36). 

The reactions of Grignard reagents with phosphorus pentahahdes have been investigated only to a limited extent (116). A complex reaction mixture was obtained from treatment of phosphorus pentachloride with phenyl Grignard reagent (113). 

Preparation of bis(4-methoxyphenyl)phenylphosphine oxide — Reaction of a Grignard reagent with a phosphorus halide... 

The reactive 3-carbonyl group in compounds of type (279) undergoes aldol condensation with active methylene compounds such reactions of isatin with indoxyl, oxindole (Section 3.3.2.5.4) and with thiophenes (Section 3.3.1.5.7.ii) have already been mentioned. These compounds also react with Grignard reagents and phosphorus halides as expected, e.g. isatin (279 Z = NH) with MeMgBr and PC13 yields (285) and (286), respectively. 

AnoAer procedure which was thought to pass through a mixed phosphorus anhydride was the acylation of Grignard reagents with an adduct formed between lithium carboxylates and triphenylphosphine dichloride (Scheme 26). The betaine (70) was the proposed tetrahedral intermediate however, since no evidence is provided, Ae reaction may have also proceeded by way of the acid chloride. Surprisingly, good yields of ketone are preserved even in the presence of excess nucleophile and no tertiary alcohol formation was observed. Triethylamine can be used for prior deprotonation of the carboxylic acid how-... 

Preparative Methods Me3SiCH2S02Cl is (1) formed in 58% isolated yield via reaction of (chloromethyl)trimethylsilane with thiourea in ethanol followed by concentration and chlorination in water, extraction, and distillation . (2) formed in 63% isolated yield by peracetic acid oxidation of (trimethylsi-lyl)methanethiol followed by treatment with phosphorus(V) chloride (3) formed in 84% yield through reaction of Me3-SiCH2Cl with magnesium followed by sequential reaction of the Grignard reagent with sulfur dioxide followed by chlorine and (4) formed in 53% yield through reaction of tetramethylsilane with sulfuryl chloride. ... 

Phosphorus(V) sulfide reacts with olefins, amines, Grignard reagents, and terpenes (6,26) as follows ... 

Preparation of the key intermediate to this series begins by reduction of the methylene phthalide, 12a, with hydriodic acid and red phosphorus. Cyclization of the acid (26) thus obtained affords the tricyclic ketone, 27. Reaction with the Grignard reagent from 3-dimethylamino-2-methylpropyl chloride affords the... 

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