A transition metal‐free iodosobenzene‐promoted direct oxidative 3‐arylation of quinoxalin‐2(H)‐ones was developed using various arylhydrazines under air. The protocol affords a variety of 3‐arylquinoxalin‐2(H)‐one derivatives in moderate to good yields. This method provides a rapid access to biologically interesting benzo[g]quinoxalinones and pyrido[3,4‐b]pyrazinones. The present methodology features high functional group tolerance including base‐sensitive groups as well as allyl‐ and benzyl‐substituted quinoxalin‐2(H)‐ones under mild reaction conditions.magnified image

An efficient protocol for the construction of 3‐carbonyl functionalized 4‐pyrones has been developed using a transition‐metal free thermal cascade reaction of diazodicarbonyls with β‐enamino esters or β‐enamino ketones. This reaction proceeds via cascade carbene generation, ketene formation via thermal Wolff‐rearrangement, nucleophilic addition, intramolecular cyclization, and elimination. This protocol provides a rapid synthetic route to diverse 2,3,5‐trisubstituted 4‐pyrone derivatives.magnified image

Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress in anxiety disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 60 anxiety disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity. Differences between HRV indices were evaluated using paired t-tests. Gender difference analysis was accomplished with ANCOVA.Results: SDNN (Standard deviation of normal RR intervals) and low frequency/high frequency (LF/HF) were significantly increased, while NN50, pNN50, and normalized HF (nHF) were significantly decreased in the upright position compared to resting state (p < 0.01). SDNN, root mean square of the differences of successive normal to normal intervals, and LF/HF were significantly increased, while nHF was significantly decreased in the psychological stress state compared to resting state (p < 0.01). SDNN, NN50, pNN50 were significantly lower in upright position compared to psychological stress and nVLF, nLF, nHF, and LF/HF showed no significant differences between them. Conclusion: The LF/HF ratio was significantly increased after both physical and psychological stress in anxiety disorder, but did not show a significant difference between these two stresses. Significant differences of SDNN, NN50, and pNN50 without any differences of nVLF, nLF, nHF, and LF/HF between two stresses might suggest that frequency domain analysis is more specific than time domain analysis. Sleep Medicine and Psychophysiology 2014；21(2)：69-73