Synthesis of Arylnaphthalene Lignan Scaffold by Gold-Catalyzed Intramolecular Sequential Electrophilic Addition and Benzannulation
作者:Vanajakshi Gudla、Rengarajan Balamurugan
DOI:10.1021/jo201918d
日期:2011.12.16
an arylnaphthalene lignan scaffold in high yields is presented. It involves a sequential intramolecular electrophilic attack of carbonyl on arylalkyne followed by benzannulation catalyzed by gold salt. AuCl3 in combination with AgSbF6 works better to effect this transformation. Selected products have been converted into arylnaphthalene lactone natural products such as justicidin E, taiwanin C, and
Base-promoted cycloaddition reactions of 1-aryl- or 1-aryl-7-substituted-4-oxahepta-1,6-diyne systems in DMSO have proven to involve an anionic intramolecularDiels-Alder process taking place even at room temperature in spite of the reaction suffering from temporary disruption of aromaticity. Although initially formed alpha-arylallenide anion can be protonated by DMSO, it can be back to the allenide
Triflic acid catalysed regioselective synthesis of substituted naphthalenes by benzannulation of carbonyls with alkynes
作者:Vanajakshi Gudla、Mokhamatam Sudheer、Chinthu Joginarayana Rao、Paul Douglas Sanasi、Venkateswara Rao Battula
DOI:10.1016/j.tet.2021.132214
日期:2021.6
An interesting and facile triflic acid catalysed annulation of α-aryl carbonyls with arylalkynes is presented for the regioselective synthesis of substitutednaphthalenes. The annulation reaction involves a sequence of electrophilic attack of carbonyl on arylalkyne and benzannulation catalysed by triflic acid. The present catalyst effects this transformation at room temperature itself. Intramolecular
作者:Vladimir Akhmetov、Mikhail Feofanov、Dmitry I. Sharapa、Konstantin Amsharov
DOI:10.1021/jacs.1c07845
日期:2021.9.22
alkynes is the key feature of carbophilic π-Lewis acids such as gold- and platinum-based catalysts. The unique catalytic activity of these compounds in electrophilic activations of alkynes is explained through relativistic effects, enabling efficient orbital overlapping with π-systems. For this reason, it is believed that noble metals are indispensable components in the catalysis of such reactions. In this
Nickel-catalyzed cocyclotrimerization of arynes with diynes; a novel method for synthesis of naphthalene derivatives
作者:Jen-Chieh Hsieh、Chien-Hong Cheng
DOI:10.1039/b415691a
日期:——
The NiBr2(dppe)–Zn system effectively catalyzes the [2 + 2 + 2] cocyclotrimerization of arynes with diynes, leading to substituted naphthalene derivatives in moderate to good yields. This cocyclotrimerization reaction shows excellent tolerance of functional groups and leads to products of 5- to 7-membered fused-ring sizes