CuI/TMEDA-Catalyzed Annulation of 2-Bromo Alkynylbenzenes with Na2S: Synthesis of Benzo[b]thiophenes
摘要:
A copper-catalyzed thiolation annulation reaction of 2-bromo alkynylbenzenes with sodium sulfide has been developed. In the presence of CuI and TMEDA, a variety of 2-substituted benzo[b]thiophenes were readily prepared in moderate to good yields by the reaction of 2-bromo alkynylbenzenes and Na2S center dot 9H(2)O.
Palladium-catalyzed synthesis of indoles via ammonia cross-coupling–alkyne cyclization
作者:Pamela G. Alsabeh、Rylan J. Lundgren、Lauren E. Longobardi、Mark Stradiotto
DOI:10.1039/c1cc11874a
日期:——
The synthesis of indoles via the metal-catalyzed cross-coupling of ammonia is reported for the first time; the developed protocol also allows for the unprecedented use of methylamine or hydrazine as coupling partners. These Pd/Josiphos-catalyzed reactions proceed under relatively mild conditions for a range of 2-alkynylbromoarenes.
Synthesis of Fluorenes<i>via</i>the Palladium-Catalyzed 5-<i>exo-dig</i>Annulation of<i>o</i>-Alkynylbiaryls
作者:Natalia Chernyak、Vladimir Gevorgyan
DOI:10.1002/adsc.200800765
日期:2009.5
The direct Pd-catalyzed intramolecular rapidly with electron-deficient benzene ring, which, in hydroarylation of o-alkynyl biaryls proceeded in highly combination with a substantial isotope effect observed, stereoselective manner producing fluorenes 2, the products of 5-exo-dig cyclization, in excellent yields. The cascade intermolecular arylation, incorporated in this transformation, allowed for efficient
Visible light-promoted radical cyclization of silicon-tethered alkyl iodide and phenyl alkyne. An efficient approach to synthesize benzosilolines
作者:Xinglong Lin、Zubao Gan、Ji Lu、Zhishan Su、Changwei Hu、Yuebao Zhang、Ya Wu、Lu Gao、Zhenlei Song
DOI:10.1039/c6cc00635c
日期:——
An efficient approach to synthesize benzosiloline has been developed by a visible light-promoted radical cyclization of silicon-tethered alkyl iodide and phenyl alkyne. The nature of the terminal substituent of alkyne...
Exclusive 5-<i>exo-dig</i> Hydroarylation of <i>o</i>-Alkynyl Biaryls Proceeding via C−H Activation Pathway
作者:Natalia Chernyak、Vladimir Gevorgyan
DOI:10.1021/ja8006534
日期:2008.4.1
The first example of the palladium-catalyzed exclusive 5-exo-dig hydroarylation of o-alkynyl biaryls has been demonstrated. In contrast to the reported earlier carbocyclizations proceeding via the Friedel-Crafts mechanism, this hydroarylation efficiently proceeds with electron-neutral and electron-deficient arenes, producing fluorene frameworks with defined stereochemistry of the double bond. On the
Conjugated metallorganic macrocycles: opportunities for coordination-driven planarization of bidentate, pyridine-based ligands
作者:Danielle C. Hamm、Lindsey A. Braun、Alex N. Burazin、Amanda M. Gauthier、Kendra O. Ness、Casey E. Biebel、Jon S. Sauer、Robin Tanke、Bruce C. Noll、Eric Bosch、Nathan P. Bowling
DOI:10.1039/c2dt31914d
日期:——
Two conjugated systems that can be constrained to planarity via metal coordination have been generated and their metal complexes studied. The potential for these architectures to be incorporated into metal-sensing arylene ethynylene/vinylene oligomers and polymers was probed by verifying that these ligands (1) bind strongly to Ag(I) and Pd(II) cations, and (2) that this event leads to complexes that are planar. Single crystal structures confirm that introduction of Ag(I) or Pd(II) cations enforces planarity in the newly formed macrocycles. Likewise, 1H-NMR titration studies reveal stoichiometric binding of Pd(II) and strong binding of Ag(I) (Ka (Ligand 1) = 1.3 × 102 M−1; Ka (Ligand 2) = 5.4 × 102 M−1) for each conjugated ligand.