- Phosphine oxides as ligands in the hydroformylation reaction
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A new rhodium-phosphine oxide system has been investigated in the hydroformylation reaction. Some of the phosphine oxide ligands of type 2-12 (i.e. R2N(CH2)nP(O)R′2, R′ = Ph, Cy; n = 0, 1, 2, 3; R = Me, Et, iPr, or NR2 = 2-pyridyl) were found to be better ligands than the phosphine analogues (i.e. R2N(CH)2PR′2) in the hydroformylation of olefins catalyzed by rhodium complexes. Detailed examination of factors controlling the selectivity for aldehydes formation revealed the following characteristics of the reaction: (a) use of ligands having bulkier amino groups decrease the yield of the aldehydes slightly; (b) ligands having amino groups with low basicity decrease the rate of the hydroformylation dramatically; (c) the electronic properties of the phosphine oxide group have no influence on the hydroformylation reaction; (d) uncoordinating solvents of low polarity such as dichloromethane, chloroform and toluene gave the best reaction rate and selectivity; (e) spectroscopic investigation of the hydroformylation of styrene catalyzed by rhodium with ligand 2 shows that the ligand is coordinated by the amino and the phosphine oxide groups under 1 atm of CO-H2 and only by the amino group under 600 lbf in-2 of CO-H2.
- Abu-Gnim, Chalil,Amer, Ibrahim
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- Triethylsiloxymethyl-N,N-dimethylamine, Et3SiOCH2NMe2: A Dimethylaminomethylation (Mannich) Reagent for O–H, S–H, P–H and Aromatic C–H Systems
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Triethylsiloxymethylamine, Et3SiOCH2NMe2, readily synthesized in high yield by the hydrosilylation reaction between Et3SiH and DMF, is an excellent (N,N-dimethylamino)methyl transfer agent to a representative range of aliphatic alcohols, thiols, and Ph2PH (E–H) materials. The reactions are almost instantaneous at room temperature in inert solvents and require no activating agents to produce E–CH2NMe2 products in high yields and illustrate the title compound as an excellent addition to the family of organic reagents. For aromatic alcohols, electrophilic substitution of the aromatic ring occurs in high yield. Crystal structures of new materials such as the cholestero–CH2NMe2 derivative, 2–4-[bis(N,N-dimethylamino)methyl]-1-naphthol, and the phosphine oxide derived from Ph2PCH2NMe2 are reported.
- Gonzalez, Paulina E.,Sharma, Hemant K.,Chakrabarty, Sanchita,Metta-Maga?a, Alejandro,Pannell, Keith H.
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p. 5610 - 5616
(2017/10/13)
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- Direct transformation of amides into α-amino phosphonates via a reductive phosphination process
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The first general method for the reductive phosphination of amides in one pot has been developed. The reactions described provide a novel access to α-amino phosphonates in good to excellent yields, cover a broad scope of substrates such as secondary and tertiary amides, and do not require a low temperature.
- Gao, Yuzhen,Huang, Zhongbin,Zhuang, Rongqiang,Xu, Jian,Zhang, Pengbo,Tang, Guo,Zhao, Yufen
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supporting information
p. 4214 - 4217
(2013/09/12)
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- Acylaminomethyl-diphenylphosphine Oxides
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Aminomethyl-diphenylphosphine oxides 3 - 7 react with mercury(II)-edta yielding the acylamino derivatives 8 - 11.The attack at a N-methyl group and the formation of the formamide 11 in high yield is surprising, the preferred rotamer of 11 is determined.
- Moehrle, Hans,Vetter, Wolfgang
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p. 427 - 430
(2007/10/02)
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- The synthesis of α-amino-substituted diphenylphosphine oxides
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Four methods with differing but overlapping specificity are described for the synthesis of α-unsubstituted as well as α-substituted (aminomethyl)diphenylphosphine oxides.The first method is based on the Arbusov reaction, the second on a Mannich-type condensation of diphenylphosphine oxide with aldehydes and secondary amines, the third on the addition of Ph2P(O)H to enamines and the fourth on the reaction of anions derived from α-unsubstituted (aminomethyl)diphenylphosphine oxides with various electrophiles.
- Broekhof, N. L. J. M.,Elburg, P. van,Gen, A. van der
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p. 312 - 316
(2007/10/02)
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