308795-35-9Relevant articles and documents
Reactions of phosphonates with organohaloboranes: New route to molecular borophosphonates
Mortier, Jacques
, p. 4266 - 4275 (2000)
Phosphonates RPO(OR′)2 (R = Me, R′ = Et (1); R = CH2Ph, R′ = Et (2); R = CH double bond CH2, R′ = Et (3); R = CH2-CH double bond CH2, R′ = Me (4); R = CH2N3, R′ = Et (5)) react with CyBCl2 (6; Cy = C6H11) in a 1:1 molar ratio in toluene at -30 °C to form the primary adducts CyBCl2·O double bond PR(OR′)2 (7-11). These products undergo a thermally induced bis-chlorodealkylation with the formation of mixtures of oligomers [-O-PR(O-)-O-BCy(O-)]n (22-26) having isovalent P-O-B groupings. Under electron impact mass spectral conditions, the ions [RPO3BCy]4-Cy, which may be attributed to tetramers [RPO3BCy]4 (22′-26′), are detected. Compounds 22′-26′ presumably possess a central cubic M4O12P4 framework that is analogous to those found in alumino- and gallophosphate materials. NMR monitoring shows that [CyBCl(μ2-O)2PR(OR′)]2 (12-16) are formed as intermediates in these reactions. These unstable dimers 12-16 possess a cyclic core analogous to the single-four-ring (4R) secondary building units (SBUs) found in zeolites and phosphate molecular sieves. Hydrolysis of 12-16 and 22-26 with methanol at 30 °C gave respectively RPO(OH)(OR′) (17-21) and RPO(OH)2 (27-31). NMR monitoring reveals that the cyclic dimer [Me2B(μ2-O)2P(CH2Ph)(OEt)]2 (35a) is the primary adduct in the reaction of PhCH2PO(OEt)2 (2) with Me2BBr (34). Heating or prolonged storage at room temperature leads to a mixture of 35a, cyclic borophosphonate Me2BC(μ2-O)2P(CH2Ph)(OEt) (35b), and the mixed anhydride of benzylphosphonic acid and dimethylborinic acid (35c).
