Origin of "hetero effect" on nitrogen inversion. Comparison of hydroxylamines and aminoxide anions
摘要:
Rate constants for nitrogen inversion in N-benzyl-N-methylhydroxylamine, NN-diethylhydroxylamine, 1-hydroxy-2,2,4,4-tetramethylpyrrolidine, their conjugate bases, and their O-acetyl derivatives in dimethylformamide-d7 were determined based on the H-1 NMR coalescence temperatures. Relative to -OH, the -O- substituent ought to either raise the barrier to inversion owing to stronger lone-pair repulsions or lower the barrier owing to weaker sigma-inductive effects. Yet nearly identical barriers to inversion, DELTA-G double dagger = 12.0-13.3 kcal/mol, are observed for both the hydroxylamine and its conjugate base. Since the observed barrier is little changed upon deprotonation, it is concluded that the pi-repulsive and sigma-inductive contributions must be nearly equal.
Compounds for the treatment of inflammatory disorders
申请人:Siddiqui Arshad M.
公开号:US20060178366A1
公开(公告)日:2006-08-10
This invention relates to compounds of the Formula (I):
or a pharmaceutically acceptable salt, solvate or isomer thereof, which can be useful for the treatment of diseases or conditions mediated by MMPs, aggrecanase, ADMP, LpxC, ADAMs, TACE, TNF-α or combinations thereof.
Compounds for the treatment of inflammatory disorders and microbial diseases
申请人:Siddiqui Arshad M.
公开号:US20070167426A1
公开(公告)日:2007-07-19
This invention relates to compounds of the Formula (I):
or a pharmaceutically acceptable salt, solvate or isomer thereof, which can be useful for the treatment of diseases or conditions mediated by MMPs, aggrecanase, ADMP, LpxC, ADAMs, TACE, TNF-α or combinations thereof.
COMPOUNDS FOR THE TREATMENT OF INFLAMMATORY DISORDERS
申请人:Guo Zhuyan
公开号:US20100145048A1
公开(公告)日:2010-06-10
This invention relates to compounds of the Formula (I):
or a pharmaceutically acceptable salt, solvate or isomer thereof, which can be useful for the treatment of diseases or conditions mediated by MMPs, ADAMs, TACE, TNF-α or combinations thereof.