Trialkyl phosphites triisopropyl phosphite

The presence of trialkyl phosphite 198 in the above mentioned reduction of the gem-dibromocyclopropanes 150 with dialkyl phosphonate and triethylamine alters the reaction course. Dialkyl cyclopropanephosphonates 199 are produced via reductive phosphonation [104]. Trialkyl phosphite participates in the carbon-phosphorous bond formation. It is supported by the exclusive formation of diisopropyl cyclopropylphosphonate in the phosphonation reaction with diethyl phosphonate and triisopropyl phosphite. (Scheme 74)... 

The allyl complex [Rh(i/3-C3H5)(cod)] reacts with trialkyl phosphites to form [RhHL2] complexes. The dimeric triisopropyl phosphite complex has already been mentioned. Trimethyl and triethyl phosphite, however, form trimeric products.64,100 The structure of the trimethyl phosphite complex (14) has been determined by X-ray crystallography.100-102... 

Dialkyl 1-alkynylphosphonates (22) were formed in good to high yields by treatment of 1-alkynyliodonium tosylates (23) with trialkyl phosphites the reaction is exothermic with trimethyl phosphite but requires heating with triethyl or triisopropyl phosphite. The addition of trimethyl or triethyl phosphite to 3-alkylene-2-oxindoles (24) has led to new product types for a, -unsaturated carbonyl compounds, i.e. a stable tri-alkoxyphosphonium zwitterion (25), and a C-alkylated phosphonate (26). ... 

The aromatic version of the Michaelis-Arbuzov reaction between trialkyl phosphites and aryl bromides in the presence of Nit II ) chloride has extensively been studied with a variety of substituted halobenzenes. It has been shown that electron-acceptor substituents, regardless of their position on the aromatic nucleus, facilitate reaction with P(III) compounds, whereas electron-donor substituents render tlie reaction more difficult. Substituents lying ortho to the halogen lower the reactivity of aryl bromides, probably because of steric hindrance. Thus, the NiCl2.catalyzed direct phosphonylation of pzzra-bromobenzaldehyde with triisopropyl phosphite at 16O C affords diisopropyl para-formylphenylphosphonate in 54% yield (Scheme 5.43). ... 

Jorgensen and coworkers reported in the same year a (3-phosphonylation of enals by trialkyl phosphites [73]. The key to this reaction was the right choice of nucleophilic additive enabling the P " to P oxidation by means of a SN2-type dealkylation reaction. The optimum reaction conditions employed an excess of benzoic acid and Nal and triisopropyl phosphite (90) as a phosphonylation reagent under diphenylprolinol catalysis. Under these conditions the reaction afforded the final products 91 in good yields and excellent enantioselectivities (Scheme 33.23). 

F-Methylation. Phosphonium salts are prepared by the quat-ernization of phosphines with methyl iodide. The displacement reaction is usually conducted in polar solvents such as acetonitrile or DMF. Dialkyl phosphonates are prepared from the reaction of trialkyl phosphites with alkyl halides, commonly known as the Arbuzov reaction. For example, diisopropyl methylphosphonate is prepared by heating a mixture of methyl iodide and Triisopropyl Phosphite (eq 34). ... 

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