115201-41-7Relevant academic research and scientific papers
Taming Ambident Triazole Anions: Regioselective Ion Pairing Catalyzes Direct N-Alkylation with Atypical Regioselectivity
Dale, Harvey J.A.,Hodges, George R.,Lloyd-Jones, Guy C.
, p. 7181 - 7193 (2019/05/10)
Controlling the regioselectivity of ambident nucleophiles toward alkylating agents is a fundamental problem in heterocyclic chemistry. Unsubstituted triazoles are particularly challenging, often requiring inefficient stepwise protection-deprotection strategies and prefunctionalization protocols. Herein we report on the alkylation of archetypal ambident 1,2,4-triazole, 1,2,3-triazole, and their anions, analyzed by in situ 1H/19F NMR, kinetic modeling, diffusion-ordered NMR spectroscopy, X-ray crystallography, highly correlated coupled-cluster computations [CCSD(T)-F12, DF-LCCSD(T)-F12, DLPNO-CCSD(T)], and Marcus theory. The resulting mechanistic insights allow design of an organocatalytic methodology for ambident control in the direct N-alkylation of unsubstituted triazole anions. Amidinium and guanidinium receptors are shown to act as strongly coordinating phase-transfer organocatalysts, shuttling triazolate anions into solution. The intimate ion pairs formed in solution retain the reactivity of liberated triazole anions but, by virtue of highly regioselective ion pairing, exhibit alkylation selectivities that are completely inverted (1,2,4-triazole) or substantially enhanced (1,2,3-triazole) compared to the parent anions. The methodology allows direct access to 4-alkyl-1,2,4-triazoles (rr up to 94:6) and 1-alkyl-1,2,3-triazoles (rr up to 99:1) in one step. Regioselective ion pairing acts in effect as a noncovalent in situ protection mechanism, a concept that may have broader application in the control of ambident systems.
Synthesis and structure-activity relationship of a novel series of heterocyclic sulfonamide γ-secretase inhibitors
Pu, Jun,Kreft, Anthony F.,Aschmies, Suzan H.,Atchison, Kevin P.,Berkowitz, Joshua,Caggiano, Thomas J.,Chlenov, Micheal,Diamantidis, George,Harrison, Boyd L.,Hu, Yun,Huryn, Donna,Steven Jacobsen,Jin, Mei,Lipinski, Kerri,Lu, Peimin,Martone, Robert L.,Morris, Koi,Sonnenberg-Reines, June,Riddell, Dave R.,Sabalski, Joan,Sun, Shaiu-Ching,Wagner, Erik,Wang, Yiqun,Xu, Zheng,Zhou, Hua,Resnick, Lynn
supporting information; experimental part, p. 4708 - 4717 (2009/10/23)
γ-Secretase inhibitors have been shown to reduce the production of β-amyloid, a component of the plaques that are found in brains of patients with Alzheimer's disease. A novel series of heterocyclic sulfonamide γ-secretase inhibitors that reduce β-amyloid levels in cells is reported. Several examples of compounds within this series demonstrate a higher propensity to inhibit the processing of amyloid precursor protein compared to Notch, an alternative γ-secretase substrate.
Heterocyclic sulfonamide inhibtors of beta amyloid production containing an azole
-
Page/Page column 14-15, (2008/06/13)
Compounds useful for lowering beta amyloid levels are provided. The compounds have the structure of formula Ia: wherein, R1 is lower alkyl, substituted lower alkyl, phenyl, substituted phenyl, benzyl, substituted benzyl, benzyloxy, substituted benzyloxy, or SO2R5; R5 is phenyl, substituted phenyl, heterocycle, substituted heterocycle, alkyl, or substituted alkyl; R2 is lower alkyl, substituted lower alkyl, CF3, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, phenyl, substituted phenyl, or cycloalkyl; R3 is hydrogen, lower alkyl, or substituted lower alkyl; R4 is phenyl, substituted phenyl, heterocycle, substituted heterocycle, thiophene, or substituted thiophene; R6 is hydrogen, lower alkyl, substituted lower alkyl, CF3, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, phenyl, substituted phenyl, cycloalkyl, or substituted cycloalkyl; W, X and Y are independently CR7 or N; and R7 is hydrogen, halogen, lower alkyl, or substituted lower alkyl.
