Radical
hydroalkylation of olefins enabled by hydrogen atom transfer
(HAT) catalysis represents a straightforward means to access C(sp
3)-rich molecules from abundant feedstock chemicals
without the need for prefunctionalization. While Giese-type hydroalkylation
of activated olefins initiated by HAT of hydridic carbon–hydrogen
bonds is well-precedented, hydroalkylation of unactivated olefins
in a similar fashion remains elusive, primarily owing to a lack of
general methods to overcome the inherent polarity-mismatch in this
scenario. Here, we report the use of visible-light-driven dual HAT
catalysis to achieve this goal, where catalytic amounts of an amine-borane
and an in situ generated thiol were utilized as the hydrogen atom
abstractor and donor, respectively. The reaction is completely atom-economical
and exhibits a broad scope. Experimental and computational studies
support the proposed mechanism and suggest that hydrogen-bonding between
the amine-borane and substrates is beneficial to improving the reaction
efficiency.
Site- and enantioselective incorporation of deuterium into organic compounds is of broad interest in organic synthesis, especially within the pharmaceutical industry. While catalytic approaches relying on two-electron reaction manifolds have allowed for stereoselective delivery of a formal deuteride (D–) or deuteron (D+) at benzylic positions, complementary strategies that make use of one-electron deuterium atom transfer and target non-benzylic positions remain elusive. Here we report a photochemical approach for asymmetric radical deuteration by utilizing readily available peptide- or sugar-derived thiols as the catalyst and inexpensive deuterium oxide as the deuterium source. This metal-free platform enables four types of deuterofunctionalization reactions of exocyclic olefins and allows deuteration at non-benzylic positions with high levels of enantioselectivity and deuterium incorporation. Computational studies reveal that attractive non-covalent interactions are responsible for stereocontrol. We anticipate that our findings will open up new avenues for asymmetric deuteration.
Objective
The paper aims to explore the status of intensive care unit (ICU) nurses' self-esteem, job satisfaction, and subjective well-being and to investigate the relationship among the three elements.
Methods
A cross-sectional survey of 224 nurses from five teaching hospitals in Tianjin, China, was conducted. Self-esteem scale, job satisfaction scale, and subjective well-being scale were used to explore the status of ICU nurses' self-esteem, job satisfaction, and subjective well-being. Correlation among the three elements was calculated by SPSS 17.0.
Results
The scores of three scales (i.e., ICU nurses' self-esteem, job satisfaction, and subjective well-being) were 27.67 ± 3.41, 43.57 ± 9.04, and 69.73 ± 11.60, respectively. The subjective well-being was significantly positively correlated with self-esteem and job satisfaction (
r
= 0.454,
P
< 0.01;
r
= 0.584,
P
< 0.01, respectively).
Conclusion
The study shows that the prevalence of subjective well-being and self-esteem with ICU nurses are at a low level, and job satisfaction is at the median level. Associations among self-esteem, job satisfaction, and subjective well-being in ICUs have been confirmed. Self-esteem and job satisfaction positively correlated with nurse subjective well-being. The higher the self-esteem and job satisfaction levels are, the stronger the subjective well-being is. The working pressure in ICUs cannot be alleviated temporarily; hence, to promote a high subjective well-being, managers and ICU nurses increase their self-esteem and job satisfaction through taking strategies that strengthen psychological construction.
The decarbonylation of primary, secondary, and tertiary alkyl-substituted acyl radicals has been investigated through photoredox catalysis. A series of quaternary carbons and γ-ketoesters have been directly constructed by the photoredox 1,4-conjugate addition of the corresponding alkyl ketoacids with electrophilic alkenes. And, the tertiary alkyl ketoacids have proved to be good precursors of tertiary alkyl radicals.
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