Trimethylphosphite, with

Again, a low-pressure, hot-wall CVD reactor was used for the depositions. Pressures ranged from 300 to 900 mTorr. Phosphorus doping was carried out with trimethylphosphite. For these experiments, some depositions were carried out with oxygen addition. In this case, deposition rates were lowered. Combining trimethylphosphite with oxygen, on the other hand, increased deposition rates. 

For example, heating of benzhydroxamoyl chloride and triphenyl-phosphorus affords triphenylphosphine oxide and benzonitrile ( ). Since the reaction of trimethylphosphite with nitrile oxides proceeds in a similar manner to afford the corresponding nitriles ( ), dehydrohalogenation and subsequent reaction of the generated nitrile oxide is indicated. 

The coupling of trimethylphosphite with p-halo-toluenetricarbonylchromium can be accomplished using Pd(dba)j and PdCl (Scheme 20.65) [221]. 

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). 

To a solution of 1.0 g (0.003 mole) of iridium tetrachloride in 0.5 ml of concentrated hydrochloric acid is added 15 ml of trimethylphosphite. This solution is added to a solution of 7.7 g (0.05 mole) of 4-/-butylcyclohexanone in 160 ml of isopropanol in a 500-ml flask equipped with a reflux condenser. The solution is refluxed for 48 hours, then cooled, and the isopropanol is removed on a rotary evaporator. The residue is diluted with 65 ml of water and extracted four times with 40-ml portions of ether. The extracts are dried with anhydrous magnesium sulfate, filtered, and the ether is removed on the rotary evaporator. The white solid residue is recrystallized from 60 % aqueous ethanol affording cis alcohol of greater than 99% purity, mp 82-83.5°. 

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... 

The removal of oxygen from 1,2,4-oxadiazole 4-oxides and polymer-supported analogues 187 can be achieved with triethyl- or trimethylphosphite, as the example in Equation (30) shows <2005JC0887>. 

Metal vapor deposition of Fe atoms with a variety of acyclic and cyclic dienes, followed by treatment of the condensate with excess trimethylphosphite, give the corresponding (diene)Fe[P(OMe)3]3 complexes in low yield109. 

Acyloin condensation of diester 30a with sodium in liquid ammonia, followed by direct hydrogenation in the presence of Adam s catalyst, furnished the diol 32 in 49% yield. Diol 32 was transformed into the cyclic thiocarbonyl derivative (80% yield) which after heating with trimethylphosphite [14] afforded twistene 33 in 50% yield. Hydrogenation of 33 gave a compound identical in all respects with twistane 1. From the diester (-)-30a (+)-twistene was obtained, m.p. 35.5-36.5 °C, +... 

Transformation of diols to the corresponding olefins by sequential treatment with l,r-thiocarbonyldiimidazole and trimethylphosphite. Also known as Corey-Winter reductive elimination, or Corey-Winter reductive olefmation. 

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]. 

It was shown (17) that phosphine exchange occurred in [AuMe(PR3)l complexes, but species with a coordination number greater than two were not observed, even with bidentate phosphorus ligands. Although such species were not observed, an associative mechanism was thought to be operative (16, 18). With trimethylphosphite also, only the two-coordinate complex [AuMe P(OMe)3 l was detected in solution (19). 

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 ). 

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. 

Phosphonic acid esters are derived from phosphonic acid (often erroneously called phosphorous acid), which is shown with some of its esters in Figure 18.3 Only two of the H atoms of phosphonic acid are ionizable, and hydrocarbon groups may be substituted for these atoms to give phosphonic acid esters. It is also possible to have esters in which a hydrocarbon moiety is substituted for the H atom that is bonded directly to the phosphorus atom. An example of such a compound is dimethylmethylphosphonate, shown in Figure 18.3. This type of compound has the same elemental formula as triesters of the hypothetical acid P(OH)3, phosphorous acid. Examples of triesters of phosphorous acid, such as trimethylphosphite, are shown in Figure 18.3. 

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... 

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