- Cascade Oxidative C?H Annulation of Thiophenes: Heck-Type Pathway Enables Concise Access to Thienoacenes
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The pursuit of efficient synthetic route to thienoacenes represents an appealing yet challenging task in the fields of both organic synthetic chemistry and organic functional materials. In this work, we disclose a rhodium-catalyzed cascade C?H annulation of phenacyl phosphoniums with (benzo)thiophenes via a Heck-type pathway to provide a new class of planar thienoacenes, which involves the formation of three Caryl-Caryl bonds and one Caryl?O bond in a single operation. The neutral S,O-heteroacenes exhibit superior stability and adopt a herringbone-like packing mode with efficient π–π stacking in the crystals, suggesting their potential in organic semiconducting materials. This work first exemplifies the superiority of cascade oxidative C?H annulation involving a Heck-type pathway in the development of concise access to heteroacenes.
- Chen, Xingyu,Yang, Yudong,Han, Weiguo,Huang, Quan,Huang, Zhenmei,You, Jingsong
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p. 12371 - 12375
(2021/05/03)
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- Strategic Approach to the Metamorphosis of γ-Lactones to NH γ-Lactams via Reductive Cleavage and C-H Amidation
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A new approach has elaborated on the conversion of γ-lactones to the corresponding NH γ-lactams that can serve as γ-lactone bioisosteres. This approach consists of reductive C-O cleavage and an Ir-catalyzed C-H amidation, offering a powerful synthetic tool for accessing a wide range of valuable NH γ-lactam building blocks starting from γ-lactones. The synthetic utility was further demonstrated by the late-stage transformation of complex bioactive molecules and the asymmetric transformation.
- Jung, Hoi-Yun,Chang, Sukbok,Hong, Sungwoo
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supporting information
p. 7099 - 7103
(2019/09/07)
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- Synthesis of Annulated Anthracenes, Carbazoles, and Thiophenes Involving Bradsher-Type Cyclodehydration or Cyclization-Reductive-Dehydration Reactions
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A conventional BF3·OEt2-mediated Bradsher-type cyclodehydration of 2-arylmethyl benzaldehydes in CH2Cl2 at room temperature gave polycyclic aromatic and heteroaromatic compounds. Alternatively, these compounds could be synthesized in better yields from 2-arylmethylbenzoic acids by triflic-acid-mediated cyclization followed by reductive dehydration.
- Rafiq, Settu Muhamad,Sivasakthikumaran, Ramakrishnan,Karunakaran, Jayachandran,Mohanakrishnan, Arasambattu K.
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p. 5099 - 5114
(2015/08/18)
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- 9-Benzylidene-naphtho[2,3-b]thiophen-4-ones as novel antimicrotubule agents - Synthesis, antiproliferative activity, and inhibition of tubulin polymerization
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A novel series of 9-benzylidene-naphtho[2,3-b]thiophen-4-ones and structurally related compounds were synthesized and evaluated for their ability to inhibit tubulin polymerization. The 4-hydroxy-3,5-dimethoxy-benzylidene analogue 15d was identified as a potent cytotoxic agent in an assay based on K562 leukemia cells. Antiproliferative activity of 15d and the 2,4-dimethoxy-3-hydroxy-benzylidene analogue 15e was additionally evaluated against a panel of 12 tumor cell lines, including multidrug resistant phenotypes. All resistant cell lines were sensitive to these compounds. Concentration-dependent flow cytometric studies showed that K562 cells as well as KB/HeLa cells treated by 15d were arrested in the G2/M phases of the cell cycle. Moreover, four compounds strongly inhibited tubulin polymerization with activities higher or comparable to those of the reference compounds. In competition experiments, the most active compounds strongly displaced radiolabeled colchicine from its binding site in the tubulin, showing IC 50 values virtually 3- to 4-fold lower than that of colchicine.
- Zuse, Anne,Schmidt, Peter,Baasner, Silke,B?hm, Konrad J.,Müller, Klaus,Gerlach, Matthias,Günther, Eckhard G.,Unger, Eberhard,Prinz, Helge
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p. 7816 - 7825
(2007/10/03)
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- Reductive cleavage of phthalides with iodotrimethylsilane
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A convenient reductive cleavage of 3-arylphthalides 1 into corresponding 2-benzylbenzoic acids and 2-(2-thienylmethyl)benzoic acid 2 by using iodotrimethylsilane is described.
- Sabitha, Gowravaram,Yadav
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p. 3065 - 3071
(2007/10/03)
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- The Synthesis of Dinaphthothiophenes
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The synthesis of dinaphthothiophene (6), dinaphthothiophene (15), dinaphthothiophene (20), dinaphthothiophene (26), dinaphthothiophene (37) and dinaphthothiophene (45) has been accomplished.
- Tedjamulia, Marvin L.,Tominaga, Yoshinori,Castle, Raymond N.,Lee, Milton L.
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p. 1143 - 1148
(2007/10/02)
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