Eliminations from (E)-2,4-Dinitrobenzaldehyde O-Aryloximes Promoted by R3N in MeCN. Effects of β-Aryl Group and Base-Solvent on the Nitrile-Forming Transition-State

Bulletin of the Korean chemical society

Bong Rae Cho¹  Sang Yong Pyun¹  Eun Mi Ryu¹ 

关键词: Elimination;    E2 and E1cb-like;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Nitrile-forming eliminations from (E)-2,4-(NO2)2C6H2CH=NOC6H4-2-X-4-NO2 (1a-e) promoted by R3N in MeCN have been studied kinetically. The reactions are second-order and exhibit Brönsted β = 0.83-1.0 and |βlg| = 0.41-0.46. The results have been interpreted in terms of highly E1cb-like transition state with extensive Cβ- H bond cleavage and limited Nα-OAr bond cleavage. Comparison with existing data reveals that the structure of the transition state changes from E2-central to highly E1cb-like either by the change of the β-aryl group from Ph to 2,4-dinitrophenyl under the same condition or by the base-solvent system variation from EtO−-EtOH to Et3N-MeCN for a given substrate (1a-e).

【 授权许可】

Unknown