24549-06-2Relevant articles and documents
Regioselectivity of the ortho- and para-semidine, and diphenyline rearrangements
Yang, Zhanhui,Hou, Shili,He, Wei,Cheng, Baoxiang,Jiao, Peng,Xu, Jiaxi
, p. 2186 - 2195 (2016/04/09)
The regioselectivity of the o-semidine, p-semidine, and diphenyline rearrangements of unsymmetrical N,N′-diarylhydrazines was studied experimentally. The results indicate that their electron-rich nitrogen atom is first protonated and then the electron-poor non-protonated nitrogen atom undergoes an N[1,3]-sigmatropic shift to the ortho-position of the electron-rich aryl rings, generating key intermediates. The intermediates can undergo (1) a direct proton transfer to give o-semidines, (2) a second N[1,3]-shift of the electron-poor nitrogen atom and then proton transfer to furnish p-semidines, and (3) a [3,3]-sigmatropic shift and subsequent proton transfer to yield diphenylines. It is the first N[1,3]-sigmatropic shift step that plays an important role in controlling the regioselectivity in the three rearrangements, further determining the structures of o-semidines, p-semidines, and diphenylines. The current results provide new insights into the o/p-semidine and diphenyline rearrangements and useful information for controlling and predicting the structures of the rearrangement products.
New diamines and a process for their production
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, (2008/06/13)
New aminoalkyl anilines having the formula: STR1 wherein k is 0 or 1; QNH2 is a residue of formula STR2 which is situated in one of the positions of the benzene ring ortho or para to the amino group and wherein n is an integer from 1 to 15, R1 is C1 -C8 alkyl, R2 is C1 -C4 alkyl or R1 and R2, together with the carbon atom to which they are attached, form a C5 -C8 cycloalkylene residue, R3 is H or C1 -C6 alkyl, C3 -C8 cycloalkyl, or C6 -C10 aryl; and R4 and R5 are H or C1 -C4 alkyl; as well as the corresponding salts of compounds of formula I with organic or inorganic acids and metal salt complexes; process for their production; and their use as intermediates for polyamides.