Nitrogen to carbon

The issue of resonance in carboxamides has recently been reexamined. Most of the structural consequences predicted by resonance are consistent with a stabilizing interaction which results in a net shift of electron density from nitrogen to carbon and oxygen A. J. Bennet, Y Somayaji, R. S. Brown, and B. D. Santarsiero, J. Am. Chem. Soc. 113 7563 (1991) A. Greenberg, T. D. Thomas, C. R. Bevilacqua, M. Coville, D. Ji, J.-C. Tsai, andG. Wu,Jl Org. Chem. 57 7093 (1992). 

Migration from nitrogen to carbon is observed also in aza-Cope rearrangement [76] Ring expansion occurs in thermal rearrangement of azindine denvauves [77] (equation 17)... 

E. Nitrogen-to-Carbon, Oxygen-to Carbon, and SulfuMo-Carbon Migration... 

A nitrogen to carbon linkage is exemplified by the formation of dichloro-1,2,4-thiadiazole (27) from phosphorus tricyanide and sulfur dichloride.32... 

The formation of tluorinated Q -hydroxy-jS-imino esters (180) by treatment of fluorinated imino ethers (179) with lithium 2,2,6,6-tetramethylpiperidide has been reported. A possible explanation for this interesting intramolecular rearrangement is proposed in Scheme 64. Acyclic imides derived from primary benzylic amines and amino acid esters have been found to undergo a novel nitrogen to carbon acyl migration via a base-generated carbanion to yield the corresponding a-amino... 

Examples exist of rearrangements in which a halogen atom migrates from annular nitrogen to carbon, or from one ring carbon to another ( halogen-dance or transmetalation). Such processes occasionally have preparative importance, and they will be covered in the appropriate sections. 

The hydrazone has all the elements of the product we want, cyclohexane, plus two nitrogen at oms. All (. ) we have to do is to move two hydrogen at oms from nitrogen to carbon. This can be done in very strong base ... 

When 4-anilino-l,1,1-trifluorobut-3-en-2-ones 17 are heated with phosphorus oxychloride, the resultant 2-(trifluoromethyl)quinolines 18 are the result of a 1,3-vinyl shift from nitrogen to carbon, followed by cyclization and dehydration.18 A wide variety of substitution patterns on the phenyl ring has been investigated. 

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