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1.
Chem Asian J ; 17(20): e202200807, 2022 Oct 17.
Article in English | MEDLINE | ID: mdl-36062560

ABSTRACT

Persistent radicals, which are generated from 2-oxindole or benzofuranone dimers, are useful tools for designing the radical-based cross-coupling reaction to provide molecules containing a quaternary carbon. The persistent radical is accessible from both the dimer and monomer; however, the reactivity difference between these substrates for the oxidative cross-coupling reaction is not fully understood, most likely because of the mechanistic complexity. Here, we present details of an aerobic cross-dehydrogenative coupling (CDC) reaction using various monomers and catechols. UV-Vis analysis and mechanistic control experiments showed that the monomer is less reactive than the dimer under aerobic conditions. Our Pd(II)-BINAP-µ-hydroxo complex significantly improved the reactivity of the monomers for the aerobic CDC reaction with catechols, yielding results comparable to those of the corresponding dimer. The procedure, which enables the generation of the persistent radical in situ, is particularly useful when employing the monomer that is not readily converted to the corresponding dimer.


Subject(s)
Catechols , Palladium , Oxidation-Reduction , Carbon
2.
J Am Chem Soc ; 139(25): 8661-8666, 2017 06 28.
Article in English | MEDLINE | ID: mdl-28581747

ABSTRACT

An enantioselective [3 + 2] cycloaddition reaction between nitrile oxides and transiently generated enolates of α-keto esters has been developed. The catalyst system was found to be compatible with in situ nitrile oxide-generation conditions. A versatile array of nitrile oxides and α-keto esters could participate in the cycloaddition, providing novel 5-hydroxy-2-isoxazolines in high chemical yield with high levels of diastereo- and enantioselectivity. Notably, the optimal reaction conditions circumvented concurrent reactions via O-imidoylation and hetero-[3 + 2] pathways.


Subject(s)
Esters/chemistry , Ketones/chemistry , Nitriles/chemistry , Oxides/chemistry , Alcohols/chemistry , Catalysis , Cycloaddition Reaction , Molecular Structure , Stereoisomerism
3.
Psychiatry Clin Neurosci ; 62(5): 503-7, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18950368

ABSTRACT

AIM: This study was undertaken 5 months after the 2004 Niigata-Chuetsu earthquake in Japan to assess factors that impacted on psychological distress and its recovery. METHODS: Three thousand and twenty-six adult victims who lived in temporary shelter and in seriously damaged areas were evaluated by questionnaire. The questionnaire queried subject profile, degree of house damage, health status, and psychological distress using a 5-point scale before, immediately and 5 months after the earthquake. RESULTS: Immediately after the earthquake, 59.3% of the subjects had psychological distress. At 5 months after the earthquake, however, this percentage decreased to 21.8%. The psychological distress immediately after the earthquake was significantly serious in victims who: (i) were female; (ii) felt stronger fear of the earthquake and the aftershocks; (iii) lived at home or office after the earthquake; and (iv) were injured due to the earthquake or suffered from sickness after the earthquake. In contrast, the factors impairing psychological recovery 5 months after the earthquake were as follows: (i) being with unfamiliar member(s) during the night after the earthquake; (ii) serious house damage; (iii) living in temporary shelter or at a relative's home after the earthquake; and (iv) physical illness after the earthquake. CONCLUSION: Despite differences between disasters, these results were consistent with those in some previous studies and may be useful for long-term mental care support.


Subject(s)
Adaptation, Psychological , Earthquakes , Stress Disorders, Post-Traumatic/diagnosis , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Fear , Female , Follow-Up Studies , Health Status , Health Surveys , Housing , Humans , Japan , Male , Middle Aged , Sex Factors , Social Environment , Stress Disorders, Post-Traumatic/epidemiology , Stress Disorders, Post-Traumatic/psychology , Surveys and Questionnaires , Wounds and Injuries/psychology
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