Phosphites reaction with Grignard reagents

Phosphines may be obtained by reaction with Grignard reagents (6.45), phosphites from reactions with alcohols (6.296,6.310) and phosphonic and phosphinic halides from reactions with metal alkyls (6.142,6.153) or other organic compounds (6.145-6.148,6.151,6.153). 

The iV-4-(benzotriazolylmethyl)-tetrahydro-l,4-benzodiazepine 59 reacted smoothly with Grignard reagents in THF to provide convenient access to substituted homologues in good yield (Scheme 25) <2002J(P1)592>. The benzo-triazole moiety can be removed reductively with NaBFLr to provide the simple jV-methyl compound, while reaction with triethyl phosphite and ZnBr2 in dry THF gave the diethylphosphonate derivative. 

Alternate routes to the methyl dialkyl phosphonite are by reaction between a trialkyl phosphite and a Grignard reagent directly, or after previous treatment with PCl ... 

The reaction of 3,4-dinitrothiophenene 89 with Grignard reagents has been shown to give thienylphenols, as exemplified by the formation of 90. A mechanistic rationale was provided to account for this unusual transformation <04EJO3566>. Synthesis of a number of 2-thienylphosphonates has been achieved by treatment of 2-chloro-3-nitrothiophenes with triethyl phosphite via a Michaelis-Arbuzov type reaction <04S668>. 

Thus it is possible to arrest the reaction of Grignard reagents with phosphites after mono displacement (9,176) with equimolar quantities of reagents and the inverse addition technique. Phosphinites were formed with reactant ratios less than 3 1 (Grignard. phosphite) but the... 

Electrophilic Reactions.— Various substituted diarylphosphine oxides have been prepared by the reaction of dibutyl phosphite with the corresponding aryl Grignard reagent. 

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