Phenyl-substituted phosphite

Shingare and co-workers have presented for the first time a successful implementation of ultrasound irradiation for the rapid synthesis of a-hydroxy phosphonates (521) and a-amino phosphonates (525) under solvent-free conditions from triethyl phosphite (524), aromatic aldehydes (523) and amines (522) using camphor sulfonic acid (CSA) (Scheme 130). One-pot, three-component Kabachnik-Fields synthesis of a-aminophos-phonates (529) from carbonyl compounds (526), primary amines (527), and dibenzyl/dimethyl/diethyl substituted phosphites (528) has been carried out in high yields, using H-beta zeolite as a reusable catalyst (Scheme 131). Zhang and co-workers have developed the nickel-catalysed Arbuzov type phosphonylation to afford phenyl substituted phosphonates (532) in the reaction of aryl triflates (530) with triethyl phosphite (531), in which KBr, as an additive, promoted the Sn2 catalytic step (Scheme 132). ... 

Electrophilic substitution of the ring hydrogen atom in 1,3,4-oxadiazoles is uncommon. In contrast, several reactions of electrophiles with C-linked substituents of 1,3,4-oxadiazole have been reported. 2,5-Diaryl-l,3,4-oxadiazoles are bromi-nated and nitrated on aryl substituents. Oxidation of 2,5-ditolyl-l,3,4-oxadiazole afforded the corresponding dialdehydes or dicarboxylic acids. 2-Methyl-5-phenyl-l,3,4-oxadiazole treated with butyllithium and then with isoamyl nitrite yielded the oxime of 5-phenyl-l,3,4-oxadiazol-2-carbaldehyde. 2-Chloromethyl-5-phenyl-l,3,4-oxadiazole under the action of sulfur and methyl iodide followed by amines affords the respective thioamides. 2-Chloromethyl-5-methyl-l,3,4-oxadia-zole and triethyl phosphite gave a product, which underwent a Wittig reation with aromatic aldehydes to form alkenes. Alkyl l,3,4-oxadiazole-2-carboxylates undergo typical reactions with ammonia, amines, and hydrazines to afford amides or hydrazides. It has been shown that 5-amino-l,3,4-oxadiazole-2-carboxylic acids and their esters decarboxylate. 

Rose and Lepper found that phosphites, especially o-substituted phenyl phosphites, enhance the catalytic activity of Pd(acac)2 or Pd(OAc)2 and affect the ratio of 47 to 48 (52). When Pd(OAc)2 and PPh3 (1 1) were used at 50°C for 1.5 hours, the yield was 20% and the ratio of 47 to 48 was... 

Obrycki, R. and Griffith, C.E., Phosphonic acids and esters. XIX. Syntheses of substituted phenyl- and arylphosphonates by the photoinitated arylation of trialkyl phosphites,. Org. Chem., 33, 632, 1968. 

The complex reacts readily with ligands such as tertiary phosphines, phosphites, or arsines to give substitution of a CO ligand on the cobalt atom. With CO, however, the complex reacts to give 2-phenylindazolone and 3-phenyl-2,4 lif, 3f/)-quinazolinedione,15 whereas the reaction with CO and hexafluoro-2-butyne affords an anilinoquinoline, probably via an intermediate complex in which the alkyne and CO have inserted into the Co—C bond.16... 

A number of ortho hindered alkyl-substituted phenyl phosphites and phosphonites were found to be effective process stabilizers for polypropylene and high density polyethylene combining more effective stabilization activity at high temperatures with good storage stability at relatively elevated humidity and ambient temperature, as well as resistance to discoloration. 

The nature of alkyl halide and the environment of the phosphorus atom make a substantial contribution to the direction of the reaction. Thus, cyclic phosphites [108], like trialkyl phosphites [110], react with preservation of the coordination of the P(III) phosphorus atom (126-132 ppm). If the alkoxyl group is substituted by amide, alkyl, or aryl, the nucleophilicity of the phosphorus atom in the corresponding amidophosphite (phosphonite) increases in comparison with the trialkyl phosphite. This probably promotes attack by 1 -haloalkyl-2-pyrrolidone at the phosphorus atom and not the oxygen, and this was confirmed experimentally. As a result of the investigated reactions amidophosphonates or ethyl phenyl phosphinates llOa-c were isolated compounds with P(III) were not detected in these cases. 

A range of diverse substituted allyl phenyl sulfoxides, which are available by addition of dimethyl cuprate to allenyl sulfoxides or more generally by alkylation of simpler analogs, - have been converted into allylic alcohols possessing predominantly ( )-stereochemistry (E Z 90 10) following simple admixture with trimethyl phosphite - or thiophenolate (MeOH, 60 C, 7 h Scheme 98 Scheme 99 for a lower selectivity see Scheme 98, entry a). ... 

Much of the work on deoxygenation of aromatic nitro and nitroso compounds by tervalent phosphorus reagents has been reviewed.3 Triethyl phosphite has been used frequently, but diethyl methylphosphonite was found to be superior for the deoxygenation of nitro compounds.3,263 The isolation of azepines from such reactions (Scheme 42) indicated the initial formation of arylnitrenes. However, a marked influence of the nucleophile upon the direction of the apparent migration of the nitrene—away or toward an ortho substituent—was noted (Scheme 42).264 Evidence that the same intermediates are involved in the azepine forming reactions from phenyl azides and nitro-benzenes was obtained by a careful examination of the azepines formed from meta-substituted derivatives (Scheme 43). The ratios of the azepines 216 and... 

No reactions occur between dialkyl phosphite salts and the A -glycosyl-C-arylnitrones 366 (R = Ph or substituted phenyl) On the other hand, reactions with tris(trimethylsi-lyl) phosphite do take place in the presence of a Lewis acid (ZnCl2, HCIO4) and proceed smoothly. Some unusual results are to be observed, particularly in relation to the nature of the catalyst otherwise, the general course of the present reaction is similar to that found for reactions of the nitrones 366 with dialkyl phosphite anions. Thus, the reaction between... 

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