A new strategy is reported for intramolecular sp(3) C-H amination under mild reaction conditions using iodoarene as catalyst and m-CPBA as oxidant. This C-H functionalization involving iodine(III) reagents generated in situ occurs readily at sterically hindered tertiary C-H bonds. DFT (M06-2X) calculations show that the preferred pathway involves an iodonium cation intermediate and proceeds via an energetically concerted transition state, through hydride transfer followed by the spontaneous C-N bond formation. This leads to the experimentally observed amination at a chiral center without loss of stereochemical information.
By developing a mild Ni-catalyzed system, a method for direct borylation of sp(2) and sp(3) C-N bonds has been established. The key to this hightly efficient C-N bond borylative cleavage depends on the appropriate choice of the nickel catalyst Ni(COD)2, ICy·HCl as a ligand, and the use of 2-ethoxyethanol as the cosolvent. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for gram-scale synthesis and late-stage C-N borylation of complex compounds.
The current study aims to explore how the decision-making style of maximizing affects subjective well-being (SWB), which mainly focuses on the confirmation of the mediator role of regret and suppressing role of achievement motivation. A total of 402 Chinese undergraduate students participated in this study, in which they responded to the maximization, regret, and achievement motivation scales and SWB measures. Results suggested that maximizing significantly predicted SWB. Moreover, regret and achievement motivation (hope for success dimension) could completely mediate and suppress this effect. That is, two competing indirect pathways exist between maximizing and SWB. One pathway is through regret. Maximizing typically leads one to regret, which could negatively predict SWB. Alternatively, maximizing could lead to high levels of hope for success, which were positively correlated with SWB. Findings offered a complex method of thinking about the relationship between maximizing and SWB.
Emojis, as a new way of conveying nonverbal cues, are widely adopted in computer-mediated communications. In this paper, first from a message sender perspective, we focus on people's motives in using four types of emojis — positive, neutral, negative, and non-facial. We compare the willingness levels of using these emoji types for seven typical intentions that people usually apply nonverbal cues for in communication. The results of extensive statistical hypothesis tests not only report the popularities of the intentions, but also uncover the subtle differences between emoji types in terms of intended uses. Second, from a perspective of message recipients, we further study the sentiment effects of emojis, as well as their duplications, on verbal messages. Different from previous studies in emoji sentiment, we study the sentiments of emojis and their contexts as a whole. The experiment results indicate that the powers of conveying sentiment are different between four emoji types, and the sentiment effects of emojis vary in the contexts of different valences.
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