Trimethylphosphite, reaction with

For these reasons, higher concentrations of alkoxide were used, firstly to increase the initial rate and secondly to pre-erve alkalinity throughout the reaction. With two equivalents of alkoxide, high yields of trialkyl phosphite were obtained within 1-2 h. at 25°. Again, the yield decreased with time owing to the subsequent oxidation, e.g. 82% trimethylphosphite and 76% tri-ethylphosphite after 1 h. 

Corey and Winter converted 1,2-diol into a cyclic thionocarbonate 4.23 on heating with thiocarbonyldiimidazole (4.22) in toluene or xylene. Thionocarbonates 4.23 can also be prepared by the reaction of diol with n-butyllithium, followed by the reaction with carbon disulfide and methyl iodide. Desulfurization-decarboxylation is carried out by heating the cyclic thionocarbonate 4.23 with trimethylphosphite, and alkene is produced (Scheme 4.17). 

This e c o-peroxide rearranged readily to form the /ra s-benzene trioxide 144 and gave trans-benzene dioxide 142 upon reaction with triphenylphosphite. A similar addition reaction occurred between singlet oxygen and indan 8,9-oxide 7 to yield a further endo-peroxide. An endo-peroxide adduct of an oxepin was also formed when singlet oxygen reacted with 1-benzoxepin 100. Upon deoxygenation with trimethylphosphite, the latter peroxide yielded an aldehyde. ... 

Completion of the monomeric unit was achieved via Swem oxidation and Arbuzov reaction with trimethylphosphite to give the phosphonate 75 in 31% overall yield from the resolved amino alcohol. Dimeric olefination was effected upon deprotonation to yield the macrocycle 76, which could be converted in 81% yield to optically active vermiculine (56) via sequential cleavage of the thioketal and ketal protecting groups. 

TRIMETHYLPHOSPHITE (I2I-45-9) Forms explosive mixture with air (flash point 130°F/54°C oc 82°F/28°C cc). Reacts with water. Incompatible with air, moisture, strong bases. Violent reaction with strong acids, nitrates, oxidizers, magnesium perchlorate. Store and handle under nitrogen blanket. 

Tris(trimethylsilyl)phosphites, analogous to trialkylphosphites, undergo Perkow reaction with a-halo carbonyl compounds to give vinyl phosphates.223 Reaction of a-chloroketone 19 with trimethylphosphite produces dimethyl enol phosphate 20, which is further converted to b is [trimethyls ilyl] esters 21 using MeaSiBr. 21 is also produced directly from a-chloroketone 19 on reacting with P(SiMe3)3. 

A value for the self-exchange rate constant for O2/OJ has been deduced by Espenson et The reaction of 02( A) with 1 probably involves the formation of HOOI, followed by a fast reaction with I to yield + H202. Intermediates in the reaction of 62 with Et2S can be trapped efficiently with trimethylphosphite. The kinetics of the reaction of (ArO)3P with (Ph0)3P-03 to form O2 and (ArO)3PO show a spontaneous and an (ArO)3P-catalyzed pathway. A complex mechanism is involved in the Cu(II)-catalyzed decomposition of hydrogen peroxide in the range pH 11 to 12. A superoxide Cu(I) complex is involved. ... 

Scheme 10 1. A representation of the Perkow reaction where 2-chloropropanal undergoes reaction with trimethylphosphite to produce dimethylvinyl phosphate and chloromethane.

Tlie starting material for this Wittig-Horner-like olefination was easily accessible by reaction of benzo-l,3-dithiolium-tetrafluoroborate with trimethylphosphite in the presence of an equimolar amount of sodium iodide in dry acetonitrile under nitrogen at room temperature (93% yield). 

The bidentate formate ligand of OsH(K2-02CH)(CO)(P,Pr3)2 is converted into a monodentate group by carbonylation. Thus, the reaction of this compound with carbon monoxide gives 0sH K1-0C(0)H (C0)2(P Pr3)2. Similarly, the addition of a stoichiometric amount of trimethylphosphite yields 0sH k -0C(0)H (C0) P(OMe)3 (P Pr3)2, and the addition of a stoichiometric amount of ethyne di-carboxylic methyl ester leads to 0sH K1-0C(0)H (C0)(r 2-Me02CC=CC02Me) (P Pr3)2, which in solution partially dissociates the alkyne. As is shown in... 

Reaction of oxyiminium cations with trimethylphosphite under catalysis with LiC104/ TMSCl results in the corresponding a-oxyaminophosphonates of type 71 (equation 45)... 

Treatment of o-phthaldialdehyde with triethylphosphite in the presence of Lewis acids yields 1-phosphoryl substituted isobenzofurans (96TL5963 see also 79JOC494). For the reaction of 3-chloro-3-phenylphthalide with trimethylphosphite see Groffits et al. [93ZOR(63)2245]. 

Halpern et al. had already stressed the importance of radical mechanisms in the oxidative addition and insertion reactions of both [Rh(OEP)]2 and Rh(OEP) [338]. Thus, [Rh(OEP)]2 reacted with trimethylphosphite according to sequence (37), forming a rhodiophosphonate Rh(PO OMe 2) (OEP) and methyl radicals which were subject to further reactions [339]. In the presence of excess P(OMe)3, they were trapped by formation of MePO(OMe)2 in more than stoichiometric quantities, indicating a radical chain process. 

Conversion of 1,2-diols to alkenes. The cyclic thiocarbonate is available from reaction of the diol with thiophosgene or thiocarbonyldiimidazole, and reacts with added trimethylphosphite via a -elimination to the alkene. 

The reaction of functionalized iminium salts 4 derived from aziridines with trimethylphosphite gives aminophosphonates 11 by a Michaelis-Arbuzov rearrangement. This reaction is general(6 ). 

The bulky ligands PPh3 and AsPh3 add to the unsubstituted end of 31 (180,181). The resulting phosphonium salt (32) is deprotonated by butyllith-ium at — 78°C to yield an ylid (33) which reacts with aldehydes in a Wittig reaction. Deprotonation with potassium tert-butoxide followed by addition of aldehyde 34 gives the E isomer (35) only [Eq. (20)] (182). Trimethylphosphite... 

When the hydrocarbon C13Hi6 (50g), obtained from 44 by displacement with trimethylphosphite, is coordinated to molybdenum [Eq. (31)], the resulting complex contains a rearranged hydrocarbon ligand, whose structure conforms with the [6 + 4] cycloadduct of 1,3-cyclohexadiene to 1,3,5-cycloheptatriene. Obviously, during the complexation reaction, C—C bonds are cleaved and otherwise reconstituted in the coordination sphere of the molybdenum (73). 

With CO, a fast addition reaction and transfer of the acetyl group from the molybdenum to the rj4-1,3-cyclopentadiene ligand is observed, and the red endo isomer of 94, [(>75-C5H5)Mo(CO)2to4-end0-C5H6COCH3)] (96), is formed in high yields [Eq. (52)]. Trimethylphosphite releases the y4-i,3-... 

Formation of 2-propyl-5-nitrobenzothiazole on reduction of 2,4-dinitro-butylth-iobenzene with sodium poly sulfite or trimethylphosphite has been observed [599], para-To] uenesul fonate 2,5-dimethyl-7-nitrobenzothiazole was obtained under the action of excess thioacetic acid on AK4-methyl-2,6-dinitrophenyl)pyridinium [600], The reaction involves the formation of 4-methyl-2,6-dinitrothiophenol acetate in which, under experimental conditions, one of the nitro groups is reduced to an amino group with subsequent cyclization, as shown in Scheme 2.109. 

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