51417-51-7Relevant articles and documents
7-Pyridylindoles: Synthesis, structure, and properties
Mudadu, Maria Salvatora,Singh, Ajay,Thummel, Randolph P.
, p. 7611 - 7617 (2006)
(Chemical Equation Presented) A series of three isomeric 7-pyridylindoles (7-PIs) are prepared where the pyridine attachment is through C2, C3, or C4. These systems are prepared by a combination of the Bartoli reaction and the Stille coupling with an appropriate pyridyl stannane. By treatment with CH 3I, the 7-PIs can be converted to their pyridinium salts. Deprotonation at the NH of these salts leads to a zwitterion which, in the 4-pyridyl system, also exists as a neutral isomer. The photophysical and NMR properties of these systems are discussed. All three pyridylindoles are analyzed by X-ray crystallography and shown to exist in different states of aggregation dictated by the formation of intra- and intermolecular H-bonds.
CONDENSED HETEROAROMATIC RING SYSTEMS. XXIII. A CONCISE SYNTHESIS OF HIPPADINE
Sakamoto, Takao,Yasuhara, Akito,Kondo, Yoshinori,Yamanaka, Hiroshi
, p. 2597 - 2600 (1993)
Hippadine, a pyrrolophenanthridine alkaloid, was synthesized in 39percent overall yield of three steps using the palladium-catalyzed cross-coupling reaction of 2,6-dibromoaniline with (Z)-1-tributylstannyl-2-ethoxyethene as a key step.
Novel Arylindigoids by Late-Stage Derivatization of Biocatalytically Synthesized Dibromoindigo
Schnepel, Christian,Dodero, Veronica I.,Sewald, Norbert
supporting information, p. 5404 - 5411 (2021/03/03)
Indigoids represent natural product-based compounds applicable as organic semiconductors and photoresponsive materials. Yet modified indigo derivatives are difficult to access by chemical synthesis. A biocatalytic approach applying several consecutive selective C?H functionalizations was developed that selectively provides access to various indigoids: Enzymatic halogenation of l-tryptophan followed by indole generation with tryptophanase yields 5-, 6- and 7-bromoindoles. Subsequent hydroxylation using a flavin monooxygenase furnishes dibromoindigo that is derivatized by acylation. This four-step one-pot cascade gives dibromoindigo in good isolated yields. Moreover, the halogen substituent allows for late-stage diversification by cross-coupling directly performed in the crude mixture, thus enabling synthesis of a small set of 6,6’-diarylindigo derivatives. This chemoenzymatic approach provides a modular platform towards novel indigoids with attractive spectral properties.
Pd-Catalyzed C-H Halogenation of Indolines and Tetrahydroquinolines with Removable Directing Group
Ahmad, Ashfaq,Dutta, Himangsu Sekhar,Kumar, Mohit,Khan, Afsar Ali,Raziullah,Koley, Dipankar
supporting information, p. 5870 - 5875 (2020/07/30)
Pd-catalyzed directing-group-assisted regioselective halogenations to C7 of indolines and C8 of tetrahydroquinolines were achieved in good to excellent yields. The practicality and utility of the developed method have been illustrated by various functiona