A convenient dealkylation of dialkyl phosphonates by chlorotrimethylsilane in the presence of sodium iodide

Inhibition of purple acid phosphatase with α-alkoxynaphthylmethylphosphonic acids

“…Chloromethylation of naphthalene (15) yielded halide 16, which was subjected to an Arbuzov-type reaction with diethyl phosphite to give 17. Again, we found that Morita's method 41 successfully dealkylated the diester (17) to give 1, albeit in low yield.…”

“…To that end, 9 was converted to its methanesulfonate ester (11) (Scheme 1) which readily underwent substitution with long-chain alcohols in hot acetonitrile in the presence of a base, yielding the desired ethers 12-14. Selective cleavage of the phosphonate ester groups of 12-14, without rupture of the benzylic ether linkage, 40 was achieved using TMSI, formed in situ from TMSCl and NaI in acetonitrile, according to Morita et al, 41 yielding the final 1-naphthylmethylphosphonic acids 5-7. The same reaction conditions were employed to prepare the a-hydroxyphosphonic acid (2) from the corresponding diethyl phosphonic ester (9) (Scheme 2).…”

Enantioselective reduction of ketophosphonates using adducts of chiral natural acids with sodium borohydride

“…Compounds (S)-3a-c were crystallized from hexane and isolated in approximately 100% optical purity (Scheme 4) The chiral menthyl groups of 3a-c were cleaved off under mild conditions by a modified procedure of Morita et al 19 The reaction of the dimenthyl α-hydroxyphosphonates 3a-c with trimethylsilyl chloride and NaI in acetonitrile led to bis(trimethysilyl)-α-hydroxyphosphonates, which were finally hydrolyzed in amixture of water/ethanol to afford the optically active α-hydroxyphosphonic acids 5a-c. The treatment of α-hydroxyphosphonates 3a-c with hydrochloric acid in water/dioxane solution also gave the corresponding free optically active phosphonic acids 5a-c in good yields.…”

Substituted 1,4‐Bisallylphosphonates: Preparation from 1‐Alkynylphosphonates and Ti(OiPr)4/2 iPrMgCl

“…Surprisingly, the methods of synthesis of 1,4-bisphosphonates are limited. Among these methods is the Michaelis-Arbuzov reaction of the appropriate alkylbromides and triethyl phosphite, [4] the Michaelis-Baker synthesis, [3,5] and catalytic cross-coupling of 1,4-diiodobutadiene with two equivalents of diethyl phosphite. [6] Recently, we began exploring the chemistry of titanacycle alkoxides.…”

“…[6] Recently, we began exploring the chemistry of titanacycle alkoxides. [7] These intermediates undergo a series of reactions with electrophiles that depends on the 1:2 stoichiometry of Ti(OiPr) 4 and iPrMgCl and of additives, such as CuBrSMe 2 . A variety of di-and trisubstituted vinylphosphonates may be prepared in a regio-and stereoselective manner (Scheme 1).…”