Estimation of Dissociation Constants (pKa'S) of Oximes from Proton Chemical Shifts in Dimethyl Sulfoxide Solution

Discovery of New Classes of Compounds that Reactivate Acetylcholinesterase Inhibited by Organophosphates

“…Phenols that are used as good leaving groups in phosphylation have significantly lower p K a values (≈7) than the phenol functionalities of 6 and 7 (p K a =8–9, [25] which are more similar to oximes). [26] …”

“…Thus, it is reasonable to suggest that certain phenols, when present in excess, could push the reaction in the reverse direction: that is, towards reactivation (Scheme ). Phenols that are used as good leaving groups in phosphylation have significantly lower p K a values (≈7) than the phenol functionalities of 6 and 7 (p K a =8–9, which are more similar to oximes) …”

Dynamic One‐Pot Three‐Component Catalytic Asymmetric Transformation by Combination of Hydrogen‐Bond‐Donating and Amine Catalysts

“…They were chosen since we believed that their intramolecular hydrogen bonding and similarity with the amine component 6 a would have a beneficial effect. For example, the oxime derived from malononitrile 10 b [pK a = 5.6 (DMSO)] [20] accelerated the reaction but unwanted side reactions and decomposition occurred and reduced the formation of 8 a (Table 1, entry 6). The one-pot reaction with malonate-derived oxime 10 c [pK a = 7.2 (DMSO)] exhibited lower activity and the reaction required 26 hours for completion; however, 8 a was formed with excellent enantioselectivity (Table 1, entry 7).…”

Dynamic One‐Pot Three‐Component Catalytic Asymmetric Transformation by Combination of Hydrogen‐Bond‐Donating and Amine Catalysts

“…For example, the oxime derived from malononitrile 10 b [pK a = 5.6 (DMSO)] [20] accelerated the reaction but unwanted side reactions and decomposition occurred and reduced the formation of 8 a (Table 1, entry 6). They were chosen since we believed that their intramolecular hydrogen bonding and similarity with the amine component 6 a would have a beneficial effect.…”