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Guoqiang Wang Liuzhou Gao Hui Chen Xueting Liu Jia Cao Shengda Chen Xu Cheng Shuhua Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(6):1708-1713
A B(C6F5)3‐catalyzed hydroarylation of a series of 1,3‐dienes with various phenols has been established through a combination of theoretical and experimental investigations, affording structurally diverse ortho‐allyl phenols. DFT calculations show that the reaction proceeds through a borane‐promoted protonation/Friedel–Crafts pathway involving a π‐complex of a carbocation–anion contact ion pair. This protocol features simple and mild reaction conditions, broad functional‐group tolerance, and low catalyst loading. The obtained ortho‐allyl phenols could be further converted into flavan derivatives using B(C6F5)3 with good cis diastereoselectivity. Furthermore, this transformation was applied in the late‐stage modification of pharmaceutical compounds. 相似文献
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Dr. Lei Zhang Takumi Oishi Liuzhou Gao Shiyu Hu Linlin Yang Prof. Dr. Wei Li Shengjun Wu Prof. Dr. Rong Shang Prof. Dr. Yohsuke Yamamoto Prof. Dr. Shuhua Li Prof. Dr. Wei Wang Prof. Dr. Guxiang Zeng 《Chemphyschem》2020,21(23):2573-2578
A new efficient metal-based frustrated Lewis pair constructed by (PtBu3)2Pt and B(C6F5)3 was designed through density functional theory calculations for the catalytic dehydrogenation of ammonia borane (AB). The reaction was composed by the successive dehydrogenation of AB and H2 liberation, which occurs through the cooperative functions of the Pt(0) center and the B(C6F5)3 moiety. Two equivalents of H2 were predicted to be liberated from each AB molecule. The generation of the second H2 is the rate-determining step, with a Gibbs energy barrier and reaction energy of 27.4 and 12.8 kcal/mol, respectively. 相似文献
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Congjun Zhu Jie Dong Xueting Liu Liuzhou Gao Yue Zhao Jin Xie Shuhua Li Chengjian Zhu 《Angewandte Chemie (International ed. in English)》2020,59(31):12817-12821
In this Communication, we report an unprecedented β‐regioselective radical inverse hydroboration (compared with ionic hydroboration) of α,β‐unsaturated amides with NHC‐BH3 enabled by photoredox catalysis. Density functional theory (DFT) calculations show that the unique photoredox cycle is a key factor to control the β‐regioselective radical hydroboration, by lowering the energy barrier in comparison with other pathways. This protocol provides a general and convenient route to construct a wide range of structurally diverse β‐borylated amides in synthetically useful yields under mild conditions. 相似文献
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ZHANG Weigang { } FENG Dejun DING Lei KAI Guiyun DONG Xiaoyi YAO Chunde {} Institute of Modern Optics Nankai University Tianjin China {} Gungxi University of Technology Liuzhou China {} National E 《Chinese Journal of Lasers》2001,10(3):174-178
1 Introduction ThefiberBragggrating (FBG) ,asanewpassivesourceelement,hasmanyimportantadvantagessuchasvolumeminuteness ,compatibilitywithfibersystem ,collectionfrequencyforwavelengthandsoforth .Thus ,FBGisplayinganimportantroleinthefibergratingsensingtechn… 相似文献
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Wentian Zou Liuzhou Gao Jia Cao Zhenxing Li Guoao Li Dr. Guoqiang Wang Prof. Dr. Shuhua Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(11):e202104004
Boron Lewis acid-catalyzed and catalyst-free hydroboration reactions of imines are attractive due to the mild reaction conditions. In this work, the mechanistic details of the hydroboration reactions of two different kinds of imines with pinacolborane (HBpin) are investigated by combining density functional theory calculations and some experimental studies. For the hydroboration reaction of N-(α-methylbenzylidene)aniline catalyzed by tris[3,5-bis(trifluoromethyl)phenyl]borane (BArF3), our calculations show that the reaction proceeds through a boron Lewis acid-promoted hydride transfer mechanism rather than the classical Lewis acid activation mechanism. For the catalyst- and solvent-free hydroboration reaction of imine, N-benzylideneaniline, our calculations and experimental studies indicate that this reaction is difficult to occur under the reaction conditions reported previously. With a combination of computational and experimental studies, we have established that the commercially available BH3 ⋅ SMe2 can serve as an efficient catalyst for the hydroboration reactions of N-benzylideneaniline and similar imines. The hydroboration reactions catalyzed by BH3 ⋅ SMe2 are most likely to proceed through a hydroboration/B−H/B−N σ-bond metathesis pathway, which is very different from that of the reaction catalyzed by BArF3. 相似文献
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Guoqiang Wang Xiaoshi Su Liuzhou Gao Xueting Liu Guoao Li Shuhua Li 《Chemical science》2021,12(32):10883
Here, we describe simple B(C6F5)3-catalyzed mono- and dihydrosilylation reactions of terminal alkynes by using a silane-tuned chemoselectivity strategy, affording vinylsilanes and unsymmetrical geminal bis(silanes). This strategy is applicable to the dihydrosilylation of both aliphatic and aryl terminal alkynes with different silane combinations. Gram-scale synthesis and conducting the reaction without the exclusion of air and moisture demonstrate the practicality of this methodology. The synthetic utility of the resulting products was further highlighted by the structural diversification of geminal bis(silanes) through transforming the secondary silane into other silyl groups. Comprehensive theoretical calculations combined with kinetical isotope labeling studies have shown that a prominent kinetic differentiation between the hydrosilylation of alkynes and vinylsilane is responsible for the chemoselective construction of unsymmetrical 1,1-bis(silanes).A B(C6F5)3/silane-based system enables the chemoselective dihydrosilylation of terminal alkynes. Using a combination of different types of hydrosilanes, a series of unsymmetrical or symmetrical 1,1-bis(silanes) could be constructed. 相似文献
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Congjun Zhu Jie Dong Xueting Liu Liuzhou Gao Dr. Yue Zhao Prof. Dr. Jin Xie Prof. Dr. Shuhua Li Prof. Dr. Chengjian Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(31):12917-12921
In this Communication, we report an unprecedented β-regioselective radical inverse hydroboration (compared with ionic hydroboration) of α,β-unsaturated amides with NHC-BH3 enabled by photoredox catalysis. Density functional theory (DFT) calculations show that the unique photoredox cycle is a key factor to control the β-regioselective radical hydroboration, by lowering the energy barrier in comparison with other pathways. This protocol provides a general and convenient route to construct a wide range of structurally diverse β-borylated amides in synthetically useful yields under mild conditions. 相似文献
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