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Functionalized flower-like mesoporous silica with a chiral organorhodium functionality incorporated within its silica framework is prepared through an assembly of chiral 4-((trimethoxysilyl)ethyl)phenylsulfonyl-1,2-diphenylethylenediamine and tetraethoxysilane under a cooperative dual-template approach followed by complexation with organorhodium complexes. Structural characterization discloses its mesostructure and well-defined single-site chiral organorhodium functionality, while electron microscopy analyses reveal the uniformly distributed three-dimensional spherical flowers constructed by the stacking of leaf-shaped nanoflakes. In particular, as a bifunctionalized heterogeneous catalyst, it shows excellent catalytic activity and high enantioselectivity in the asymmetric transfer hydrogenation of aromatic ketones in aqueous medium (more than 99% conversion and up to 97% ee). The superior catalytic performance is attributed to the synergistic effect of the salient cetyltrimethylammonium bromide phasetransfer function and confined chiral organorhodium catalytic nature. Furthermore, this heterogeneous catalyst could be recovered easily and reused repeatedly (ten times) without affecting its ee value, showing a practical application in asymmetric synthesis. † Electronic supplementary information (ESI) available. See

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Purpose The purpose of this paper is to empirically analyze whether and how managerial overconfidence affects stock price crash risk. Design/methodology/approach Based on a large sample of Chinese non-state-owned firms from 2000 to 2012, this study employs methods including multiple linear regression model, Heckman two-stage treatment effect procedure, firm fixed effects model and event study to clarify the causality relationship between managerial overconfidence and crash risk. Findings The authors find that firms with overconfident managers (chief executive officer or board chairs) are more likely to experience future stock price crashes than firms with non-overconfident managers. The effect of overconfidence on crash risk is more pronounced for firms with low transparency, suggesting that firm opacity facilitates overconfident managers’ bad news hoarding activities, which, in turn, increases stock price crash risk. The authors also show evidence that overconfident managers tend to disclose good news in a timely manner. Originality/value The authors add to the growing literature on stock price crash risk. Specifically, the authors find that the cognitive bias of board chair plays an important role in the bad news hoarding activities, thereby increasing the likelihood of stock price crash. This study also contributes to the literature that addresses the effects of managerial overconfidence on corporate finance issues.