27311-65-5Relevant articles and documents
N -Hydroxyphthalimide/benzoquinone-catalyzed chlorination of hydrocarbon C-H bond using N -chlorosuccinimide
Li, Zi-Hao,Fiser, Béla,Jiang, Biao-Lin,Li, Jian-Wei,Xu, Bao-Hua,Zhang, Suo-Jiang
supporting information, p. 3403 - 3408 (2019/04/01)
The direct chlorination of C-H bonds has received considerable attention in recent years. In this work, a metal-free protocol for hydrocarbon C-H bond chlorination with commercially available N-chlorosuccinimide (NCS) catalyzed by N-hydroxyphthalimide (NHPI) with 2,3-dicyano-5,6-dichlorobenzoquinone (DDQ) functioning as an external radical initiator is presented. Aliphatic and benzylic substituents and also heteroaromatic ones were found to be well tolerated. Both the experiments and theoretical analysis indicate that the reaction goes through a process wherein NHPI functions as a catalyst rather than as an initiator. On the other hand, the hydrogen abstraction of the C-H bond conducted by a PINO species rather than the highly reactive N-centered radicals rationalizes the high chemoselectivity of the monochlorination obtained by this protocol as the latter is reactive towards the C(sp3)-H bonds of the monochlorides. The present results could hold promise for further development of a nitroxy-radical system for the highly selective functionalization of the aliphatic and benzylic hydrocarbon C-H.
Discovery of functionally selective 7,8,9,10-tetrahydro-7,10-ethano-1,2,4- triazolo[3,4-a]phthalazines as GABAA receptor agonists at the α3 subunit
Russell, Michael G. N.,Carling, Robert W.,Atack, John R.,Bromidge, Frances A.,Cook, Susan M.,Hunt, Peter,Isted, Catherine,Lucas, Matt,McKernan, Ruth M.,Mitchinson, Andrew,Moore, Kevin W.,Narquizian, Robert,Macaulay, Alison J.,Thomas, David,Thompson, Sally-Anne,Wafford, Keith A.,Castro, José L.
, p. 1367 - 1383 (2007/10/03)
We have previously identified the 7,8,9,10-tetrahydro-7,10-ethano-1,2,4- triazolo[3,4-a]phthalazine (1) as a potent partial agonist for the 0.3 receptor subtype with 5-fold selectivity in binding affinity over α1. This paper describes a detailed investigation of the substituents on this core structure at both the 3- and 6-positions. Despite evaluating a wide range of groups, the maximum selectivity that could be achieved in terms of affinity for the α3 subtype over the α1 subtype was 12-fold (for 57). Although most analogues showed no selectivity in terms of efficacy, some did show partial agonism at α1 and antagonism at α3 (e.g., 25 and 75). However, two analogues tested (93 and 96), both with triazole substituents in the 6-position, showed significantly higher efficacy for the α3 subtype over the α1 subtype. This was the first indication that selectivity in efficacy in the required direction could be achieved in this series.