- Dephosphinylative [4 + 2] Benzannulation of Phosphinyl Ynamines: Application to the Modular Synthesis of Polycyclic Aromatic Amines
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A series of 9-amino-10-halophenanthrenes were synthesized through a one-pot process, including dephosphinylative Sonogashira–Hagihara coupling of 2-bromobiphenyls with air-stable phosphinyl ynamines, followed by halonium-promoted [4 + 2] benzannulation of the resulting 2-(aminoethynyl)biphenyls. Nonsubstituted and methyl-substituted 2-bromobiphenyls rapidly underwent the Sonogashira–Hagihara aminoethynylation and the halogenative Friedel–Crafts benzannulation to provide the corresponding amino(halo)phenanthrenes in high yields, while electron-sufficient and -deficient substrates did slowly undergo the former and the latter to result in low yields, respectively. This protocol worked well for the syntheses of highly π-extended aminophenanthrenes and aminobenzonaphthothiophenes with different optical properties. Further application of this approach between 2,2″- and 2′,5′-dibromo-p-terphenyls with phosphinyl ynamines led to the regioselective formation of 6,13-diamino-5,12-dihalo- and 5,12-diamino-6,13-dihalo-dibenz[a,h]anthracenes via dual aminoethynylation and [4 + 2] benzannulation. The obtained analogues showed different ultraviolet–visible absorption and photoluminescence spectra with different emission quantum yields in CH2Cl2 solution and the powder state.
- Okuda, Yasuhiro,Fujimoto, Mayo,Akashi, Haruo,Orita, Akihiro
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supporting information
p. 17651 - 17666
(2021/12/13)
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- Rhodium-Catalyzed Synthesis of Chiral Monohydrosilanes by Intramolecular C?H Functionalization of Dihydrosilanes
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The preparation of chiral monohydrosilanes remains a rarely achieved goal. To this end a Rh-catalyzed desymmetrization of dihydrosilanes by way of intramolecular C(sp2)?H functionalization under simple and mild conditions has now been developed
- Ma, Wenpeng,Liu, Li-Chuan,An, Kun,He, Tao,He, Wei
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supporting information
p. 4245 - 4251
(2020/12/25)
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- Palladium-catalyzed relay C–H functionalization to construct novel hybrid-arylcyclophosphorus ligand precursors
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A new relay C–H functionalization of di([1,1′-biphenyl]-2-yl)phosphine oxide to obtain esterified and hydroxylated products with different hypervalent iodines as oxidants under palladium catalysis is disclosed. This reaction provides a more effective and concise strategy for the synthesis of novel structural hybrid-arylcyclophosphorus ligand precursors with a wide range of substrates and good functional group tolerance.
- Bai, Peng-Bo,Wang, Juan,Yang, Shang-Dong
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supporting information
(2021/11/17)
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- Ag-Catalyzed Cyclization of Arylboronic Acids with Elemental Selenium for the Synthesis of Selenaheterocycles
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A general method for the synthesis of five-membered and six-membered selenaheterocycles through Ag-catalyzed C?Se bond-forming reaction is reported. This reaction proceeds via intramolecular cyclization of arylboronic acids with selenium powder. Preliminary mechanism studies demonstrate that this transformation involves a selenium-centred radical intermediate. (Figure presented.).
- Gao, Wen-Xia,Huang, Xiao-Bo,Liu, Miao-Chang,Wu, Hua-Yue,Zhang, Xue,Zhou, Yun-Bing
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supporting information
p. 5639 - 5644
(2020/11/30)
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- Pd(II)-catalyzed C(sp2)-H hydroxylation with R 2(O)P-coordinating group
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A novel R2(O)P-directed Pd(II)-catalyzed C-H hydroxylation to synthesize various substituted 2′-phosphorylbiphenyl-2-ol compounds is described. Notably, the reaction operates under mild conditions and shows good functional group tolerance, high selectivity, and yield.
- Zhang, Hong-Yu,Yi, Hong-Ming,Wang, Gang-Wei,Yang, Bin,Yang, Shang-Dong
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supporting information
p. 6186 - 6189
(2014/01/17)
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- Ni(cod)2/PCy3-catalyzed cross-coupling reactions of dihaloarenes with arylboronic acids
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The Ni(0)-catalyzed cross-coupling reactions of dihaloarenes with one equivalent of arylboronic acids is described. The Ni(cod)2/PCy 3 was identified as the best catalyst system to achieve a double cross-coupling reaction, likely via an efficient preferential oxidative addition. Georg Thieme Verlag Stuttgart New York.
- Dong, Cheng-Guo,Hu, Qiao-Sheng
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supporting information
p. 2121 - 2125
(2012/11/07)
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