N, C-Dianions

Chan, M.C.-W. and Che, C.-M. (1998) Application of 2,6-diphenylpyridine as a tridentate [C N C] dianionic ligand in organogold(III) chemistry. Structural and spectroscopic properties of mono- and binuclear transmetalated gold(III) complexes. Organometallics, 17, 3505-3511. 

Reaction of lithium salts, formed from ethyl 4-substituted 6-methyl-2-oxo-l,2,3,4-tetrahydropyrimidine-5-carboxylates with BuLi, and 1,3-dibromopropane yielded 3-substituted l-oxo-2,3,5,6,7,8-hexahydropyr-ido[l,2-c]pyrimidine-4-carboxylates (08T11718). Reaction of N,C-dianion,... 

Direct lithiation of 3-(Boc-amino)-5-methylisoxazole and 5-(Boc-amino)-3-methylisoxazole gives N/C-dianions which react with a variety of electrophiles to afford 4-substituted aminoisoxazoles in good yields <1996TL3339>. Metallation of 3-substituted isothiazoles <2002JOC2375, 2004JOC1401> and isoselenazoles proceeds satisfactorily at the 5-positions. 

Even Ar-hydrogen-4,5-dihydroimidazolcs can be side-chain deprotonated when the side-chain carbon is also benzylic thus, the N,C-dianion formed from 497 can be N,C-dialkylated producing 498, for example, <1998JOC8107>. 

An ethereal soln. of phenyllithium added to startg. chlorallylamine in THF at —78° under argon, stirred for 30 min at the same temp., a soln. of Li-naphthalenide in the same solvent added, the mixture stirred for a further 2 h, water added, and allowed to warm to room temp, overnight - N-allylaniline. Y 93%. F. electrophiles, also syntheses via N-acylallylamine N,C-dianions, and prepn. of propargylamines from N-alkyl derivs., s. J. Barluenga et al., J. Chem. Soc. Perkin Trans. I 1989, 553-7. 

A soln. of cyanamide in THF followed by a soln. of pivaloyl chloride in the same solvent added dropwise over 15 min via syringe pump to a suspension of KH in THF at —78°, and the vigorously stirred mixture allowed to warm to room temp, overnight pivaloylcyanamide. Y 83.5%. Products were pure when formed, but became unstable on exposure to air. F.e. and reactions via N,C-dianions s. J.L. Belletire, Synth. Commun. 18, 2063-71 (1988). 

Regio- and geo-specific syntheses with 2-ethyleneamines via N,C-dianions... 

Hydroxycarboxylie acid amides from ketones N,C-Dianions as intermediates Inverse neutralization... 

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