On water: iodine-mediated direct construction of 1,3-benzothiazines from <i>ortho</i>-alkynylanilines by regioselective 6-<i>exo-dig</i> cyclization
作者:Kapil Mohan Saini、Rakesh K. Saunthwal、Shiv Kumar、Akhilesh K. Verma
DOI:10.1039/c9ob00128j
日期:——
Herein, we report the 6-exo-dig ring closure of ortho-alkynylanilines with readily available aroyl isothiocyanate. An environmentally benign, metal- and base-free, iodine promoted cascade synthesis of highly functionalized (benzo[1,3]thiazin-2-yl)benzimidic acids has been accomplished via in situ generated ortho-alkynylthiourea. The established methodology employs the abundant chemical feedstock of
<i>p</i>-Toluenesulfonic Acid Promoted Annulation of 2-Alkynylanilines with Activated Ketones: Efficient Synthesis of 4-Alkyl-2,3-Disubstituted Quinolines
Reactions between readily available 2-alkynylanilines and activatedketones such as β-keto esters promoted by p-toluenesulfonicacid afford 4-alkyl-2,3-disubstitutedquinolines in good to excellent yields. The generality of substituents at the other end of the triple bond of 2-alkynylanilines makes the method a valuable approach to diversified 4-alkylquin-olines, which are difficult to obtain by classical
Copper-catalyzed tandem reaction of 2-alkynylanilines with benzoquinones: efficient access to 3-indolylquinones
作者:Raveendra Jillella、Chang Ho Oh
DOI:10.1039/c8ra03712d
日期:——
A simple, mild, catalytic and efficient method for the straightforward synthesis of an interesting class of 2-aryl/alkyl-substituted-3-indolyl quinones in good to high yields is reported for the first time. This atom-efficient method proceeds via copper-catalyzed one-pot sequential intramolecular hydroamination (C–N bond formation) of 2-alkynylanilines followed by oxidative C–C coupling with benzoquinones
Triflic acid-promoted cycloisomerization of 2-alkynylphenyl isothiocyanates and isocyanates: a novel synthetic method for a variety of indole derivatives
A new approach towards the synthesis of indolederivatives via triflic acid-promoted cycloisomerization with rearrangement of 2-(alkyn-1-yl)phenylisothiocyanates and 2-(alkyn-1-yl)phenylisocyanates has been achieved. By this methodology, structurally diverse types of indolederivatives such as thieno- and furo-indoles, spiro-indolethiones, spiro-oxindoles, and 3-alkylidene-oxindoles were synthesized
Domino Process in Silver-Catalyzed Reactions of <i>N</i>-Arylformimidates and Active Methylene Compounds Involving Cycloisomerization and 1,3-Alkenyl Shift
作者:Chang Ho Oh、Swastik Karmakar、HyoSeung Park、YoungCheon Ahn、Jung Wook Kim
DOI:10.1021/ja9106226
日期:2010.2.17
3-disubstituted indoles from alkyne iminoethers 1 that employs a domino process involving Ag-catalyzed condensation followed by a tandem Ag-induced cycloisomerization and 1,3-alkenyl shift to Ag-activated carbon. This methodology can be useful in regioselectively constructing 3-alkylated indoles, which are part of the structures of biologically active compounds and important alkaloids.