Complexes and triethylamine

Alkyl- and aryl-pyridazines can be prepared by cross-coupling reactions between chloropyridazines and Grignard reagents in the presence of nickel-phosphine complexes as catalysts. Dichloro[l,2-bis(diphenylphosphino)propane]nickel is used for alkylation and dichloro[l,2-bis(diphenylphosphino)ethane]nickel for arylation (78CPB2550). 3-Alkynyl-pyridazines and their A-oxides are prepared from 3-chloropyridazines and their A-oxides and alkynes using a Pd(PPh3)Cl2-Cu complex and triethylamine (78H(9)1397). 

The sol-gel entrapment of the metal complexes [Ru(p-cymene)(BINAP)Cl]Cl and the rhodium complexes formed in situ from the reaction of [Rh(COD)Cl]2 with DlOP and BPPM has been reported by Avnir and coworkers [198]. The metal complexes were entrapped by two different methods the first involved addition of tetramethoxysilane to a THF solution of the metal complex and triethylamine, while the second method was a two-step process in which aqueous NH4OH was added to a solution of HCl, tetramethoxysilane and methanol at pH 1.96 followed by a THF solution of the appropriate metal complex. The gel obtained by each method was then dried, crushed, washed with boiling CH2CI2, sonicated in the same solvent and dried in vacuo at room temperature until constant weight was achieved. Hydrogenation of itaconic acid by these entrapped catalysts afforded near-quantitative yields of methylsuccinic acid with up to 78% e.e. In addition, the catalysts were found to be leach-proof in ethanol and other polar solvents, and could be recycled. 

Racemization of (S)-l-phenylethanol in the presence of an Ru p-cymerie binu-clear complex and triethylamine was much faster in [BMIm][BF4] or [BMIm][PF,s] than in toluene [136]. A range of chiral alcohols (Figure 10.17) were resolved in the presence of this complex and immobilized PsL. The reactions were performed in [BM Im][PF6] with the activated ester 2,2,2-trifluoroethyl acetate as the acyl donor (Figure 10.17). A hydrogen donor was required to prevent the formation of partially oxidized byproducts. Enantiomerically pure acetates were isolated in high yield (>85%). 

P-NMR spectra of a 1 5 mixture of the BINAP-Rh+ complex and triethylamine in acetone- ... 

Alkylation of olefins. 1-Alkenes (and 1,2-disubstituted alkenes) can be alkylated primarily at the 2-position by stabilized carbanions in the presence of this Pd(II) complex and triethylamine. The reaction involves a palladium complex of the alkenc followed by 8-elimination of Pd(0) to give the unsaturated product, which can be hydrogenated if desired before work up. ... 

In order to access the (Z) diastereomer, Lopez has reported a formal trans-hydroboration of terminal enyne using pinacolborane in the presence of a Rh(I) complex and triethylamine [180] (Scheme 93) The yield is highly influenced by the presence of substituents on the enyne substrate. 

Figure 3-14 shows an induction period in the reaction of carbon suboxide (O=C=C=C=0) with triethylamine. This reaction is complex and is not yet... 

Germenes readily form complexes with such Lewis bases as diethyl ether,11,51 tetrahydrofuran,52 and triethylamine.51 The germanimine18 and... 

Eley, D. D., and H. Watts Aluminium Halide Complexes with Pyridine, Trimethylamine and Triethylamine, Part I. J. chem. Soc. [London] 1952, 1914. 

A series of tricyclic spiroperphosphoranides 231 (R = Me) have been synthesized by the reaction of spirophosphor-anes 230 with tetrachlorocatechol in the presence of NEt3. The same complexes could also be synthesized via addition of tetrachlorocatechol to spiroperphosporanides generated from the treatment of 230 with hexafluoropropan-2-ol and triethylamine (Scheme 33) <2000JOC304>. 

Palladium catalyzed reaction of aryl halides and olefins provide a useful synthetic method for C-C bond formation reaction [171, 172], The commonly used catalyst is palladium acetate, although other palladium complexes have also been used. A sol-vent-free Heck reaction has been conducted in excellent yields using a household MW oven and palladium acetate as catalyst and triethylamine as base (Scheme 6.51) [173], A comparative study revealed that the longer reaction times and deployment of high pressures, typical of classical heating method, are avoided using this MW procedure. 

R = H, X = S, A = Et3N and Py). In solution the former is mainly in an ionic form the latter exists as a complex. The basicity of the amine is assumed to be important. Triethylamine is a stronger base than pyridine and the ionic form is stabilized. When the proton affinity is weak, the basicity in relation to the B(III) atom, a Lewis acid, plays an important role. This involves an equilibrium shift toward the complex. This assumption is confirmed by an easy displacement of pyridine by triethylamine. The reverse process demands more severe conditions. In the NMR spectra of the triethylamine complex the signal is shifted from 22 to 42 ppm as pyridine is added. The absence of signals of two separate forms is evidence in favor of their fast interconversion. The chemical shift of the signal in 3IP spectra is 22 ppm (EtOH), 26 ppm (Py, DMFA), and 42 ppm (EtOH, Py) for complexes with triethylamine and pyridine. 

Both forms have been isolated in a number of cases [Eq. (90)]. The ionic component has been obtained when diphenylboryloxymethyl(oxy-methyl)phenylphosphine sulfide is treated with triethylamine or pyridine. In the case of pyridine the complex is isolated by careful evaporation of benzene solvent. Unlike the ionic form, which is crystalline, the complex form is a liquid. In its IR spectrum there is an intense absorption of the hydroxyl groups and no absorption of the H—N+ bond. Spectra of benzene solutions of the complex and ionic forms are identical. With crystallization the complex form rearranges into the ionic form. 

DR. NORTON An excellent attempt to observe such hydrogen bonding was made recently by Fachinetti, et al. [Calderazzo, F. Fachinetti, G. Marchetti, F. Zanazzi, P. F. J. Chem. Soc., Chem. Commun. 1981, 181]. They took hydridocobalttetracarbonyl and triethylamine, and crystallized out a species which one can only describe as the tetracarbonylcobaltate of protonated triethylamine. They proposed some type of interaction between the hydrogen and a face of the cobalt tetrahedral complex, but it was clear that the interaction was almost entirely with nitrogens. The conclusion I would draw is that the complex appears to proceed directly to full protonation of the amine without any observable evidence for a hydrogen bonded intermediate. 

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