A -Formamides

Figure 9 Logarithmic plots of the heights of the first peak m the PCF against Taft s (1 parameters (a) formamide (b) formamidic acid.

Disubstituted formamides can give addition of 2 mol of Grignard reagent. The products of this reaction (called Bouveault reaction) are an aldehyde and a tertiary amine.The use of an amide other than a formamide can give a ketone instead... 

The Leuckart-Wallach reaction is the oldest method of reductive amination of carbonyl compounds. It makes use of formamide, formic acid or ammonium formate at high temperature. The final product is a formamide derivative, which can be converted to an amine by reduction or hydrolysis. The method has been applied to the preparation of 1,2-diamines with a norbornane framework, which are interesting rigid analogues of 1,2-diaminocyclohexanes. As a matter of fact, starting from N-acetyl-2-oxo-l-norbornylamine 222, the diamide 223 was obtained with excellent diastereoselectivity and then converted to the M-methyl-N -ethyl derivative 224 by reduction with borane [ 104] (Scheme 34). On the other hand, when the reac-... 

Finally, it s worth mentioning the formamide group. Although this looks like a special case of a secondary amide, rotamers of different intensity are often seen. Compounds with a formamide attached to an aromatic ring can give particularly complex spectra. Not only does the NH proton couple to the CHO proton, with a coupling of about 2-3 Hz in the cis isomer, and 8-9 Hz in the trans isomer, but, any aromatic protons ortho to the formamide are also split out in the rotamers ... 

Fig. 5.10 Current-time behavior during 20 V potentiostatic anodization of a Ti foil (99.8 % pure) in a formamide solution containing 5% H2O and identical molar concentrations (0.27M) of fluoride ion bearing compounds with four different cationic species Hydrogen (H ), Ammonium (NH4 ), Tetrabutylammonium ([C4Hg]4N ), and Benzyltrimethylammonium...

In the other two studies, selenosulphate was used. In one, a formamide complex of Hg, made by dissolving HgO in formamide, was used [154]. The solution was made ca. 0.5 M in NaOH, and a trace of polyvinyl pyroUidone was added. The deposition was carried out at room temperature. The polyvinyl pyrollidone slowed the deposition somewhat and apparently improved fihn uniformity and adherence as well as slightly increased terminal thickness (500 mn). It was noted that films were not obtained with the usual complexants, such as ammonia, triethanolamine, and cyanide. It is not mentioned in which way these complexants were unsuitable ammonia and triethanolamine might be too weak, resulting in immediate precipitation in solution. Also, addition of ammonia to some mercuric salts tends to lead to precipitation of insoluble products. Cyanide, however, is a very strong com-plexant and would be expected to control such bulk precipitation better than formamide. Iodide, a strong complex for Hg (and successfully used to deposit HgS, as described earlier), resulted in film deposition but with poor reproducibility. 

In another method for the conversion RM — RCONR), Grignard reagents and organoli-thium compounds are treated with a formamide HCONRj to give the intermediate RCH(OM)NR2, which is not isolated, but treated with PhCHO or PhiCO to give the product... 

Figure 2.2 Pressure profiles recorded from microwave heating at 180°C of (A) formamide and KOf-Bu (B) a preparative aminocarbonylation reaction with 4-bromotoluene and formamide and (C) pure formamide (Smith Synthesizer).

Wan, Y.Q., Alterman, M., Larhed, M. and Hallberg, A., Formamide as a combined ammonia synthon and carbon monoxide source in fast palladium-catalysed aminocarbonylations of aryl halides, /. Comb. Chem., 2003, 5, 82-84. 

Nevertheless, there is one report on the selective transformation of an electron-rich aromatic /V-mcthyl tertiary amine into a formamide in the presence of a primary alcohol.150... 

Fragmentation of the initially formed chromate ester gives formaldehyde and an iminium ion that is trapped by dichromate. The resulting chromate ester evolves to a formamide. 

Banhidai, B. Schollkopf, U. (Dimethylcarba-moyljlifhium from DMF and LDA synthesis of a-hydroxy N,N-dimefhylcarboxamides. Angew. Chem. Int. Ed. 1973, 32, 836-837. Cunico, R. F. Carbamoylsilanes from the in situ metalation-silylation of a formamide. Tetrahedron Lett. 2001, 42,1423-1425. 

For complexes of type 10 (with a hydrogen at the carbene carbon) a synthesis was worked out in which a formamide is first reacted with K2[Cr(CO)j] followed by reaction with TMSCI [7]. This way, the non-racemic formamide 12 leads to the chirally modified amino carbene complex 13, which serves as starting material for the diastereoselective synthesis of various optically active yff-lactams [8]. An example is the (formal) total synthesis of 1-carbacephalothin 16, a carbon analog of the cephalosporins (Scheme 5) [8b]. In this case, the complex 13 is irradiated in the presence of in situ prepared imine 14 to afford the /(-lactam with high dia-stereoselectivity but only in modest yield. The product (15) could (in principle) be converted in to the target compound 16. 

Ge4Sio]" and [Fe4S4CLi] clusters was synthesized from a formamide solution containing the surfactant cetylpyridinium bromide. ... 

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