Methylamine complexes

All three necks of the flask should be vertical and not set at an angle. This is to prevent the accumulation of large amounts of the methylamine complex of titanium tetrachloride on the sides of the reaction flask. 

Computational approach. Lee and Houk conducted calculations using a methyl-ammonium ion to mimic the key lysine of the enzyme active site.16 They chose this model because, even though no crystal structures had been solved at the time, a lysine was known to be essential for catalysis.60 The reaction of orotate + CH3NH3 to form a carbene-methylamine complex was thus examined in various dielectrics using the SCI-PCM SCRF method in Gaussian 94.30 31 48 Solvation energies computed at the RHF/6-31 + G level were used to correct gas phase MP2/ 6-31 + G energies and obtain AH values for reaction in solution. 

Results. Lee and Houk were the first to model part of the ODCase active site when they calculated decarboxylation energetics for orotate in the presence of methylammonium ion as a mimic of the key active site lysine. Based on their conclusion that 4-protonation is an energetically favorable pathway (see above), they calculated the energy of reaction of orotate (la) plus Cf NHj to form a carbene-methylamine complex plus C02 (equation 1). 

The structure of the hexakis complex of NH2OH has also been reported recently (14). In contrast to the methylamine complex the mean... 

Simultaneous reduction of the benzyl ethers and the azide proved unsatisfactory in the presence of methyl esters. An alternate procedure utilized thioacetic acid to reductively A-acetylate the azide. Thus, treatment of III.18 and III.19 with thioacetic acid afforded the corresponding 2-deoxy-2-acetamido derivatives III.20 and III.21, respectively. Hydrogenolysis followed by sulfation with the sulfur trioxide-tri-methylamine complex gave the corresponding 4- and 6-O-sulfated disaccharides III.22 and III.23. Final saponification of 111.22 and III.23 with aqueous sodium... 

O-Dechloroacetylation of IV.61 by treatment with thiomea gave IV.62, which was subsequently reprotected as the hydrogenolyzable 4-methoxybenzyl ether with 4-methoxybenzyl trichloroacetimidate and triflic acid under phase transfer catalysis conditions [104]. Saponification of the benzoate and methyl esters with lithium hydroperoxide followed by methanolic sodium hydroxide and acidification then gave the acid IV.63. O-Sulfonation of IV.63 was achieved with the sulfur trioxide-tri-methylamine complex to give the disulfate IV.64 as the sodium salt. Finally, hydro-genolysis of IV.64 with Pd/C in aqueous methanol afforded the target disaccharide IV.51. 

Infrared spectra of methylamine complexes, [Pt(CH3NH2)2X2] (X a halogen), have been studied by Wait et al. and Kharitonov et al. Far-infrared spectra of [MfRiNH)2X2]- [M=Zn(ll) or Cd(ll) R = ethyl or n-propyi X = Cl or Br] type complexes have also been reported/ Chatt and co-workers studied the effect of hydrogen bonding on the NH stretching frequencies of... 

FREQUENCY OF THE METAL-LIGAND PREDOMINANTLY STRETCHING VIBRATIONS OF PLATINUM METHYLAMINE COMPLEXES. 

FREQUENCY OF THE METAL-LIGAND PREDOMINANTLY STRETCHING VIBRATIONS OF PLATINUM METHYLAMINE COMPLEXES. //ENGLISH TRANSLATION OF ZH. NEORG. KHIM. 

The problem in interpreting the "steric" effects in the ammonia and methylamine complexes of Co(III) and Cr(III) might have been avoided if there were some method of estimating the sizes of the ligands and therefore anticipating whether steric effects were really significant in a particular system. 

In benzene solution the rate law for oxidation 2,6-dimethyl-phenol by O2 catalyzed by the bis(3-(salicylideneamino)propyl) methylamine complex of cobalt(II), [Co(SMDPT)], is (35), which suggests participation of a C0-O2 complex in which the oxygen is activated to H abstraction. 

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