143360-82-1Relevant articles and documents
First heterogeneously palladium-catalysed fully selective C3-arylation of free NH-indoles
Cusati, Giuseppe,Djakovitch, Laurent
, p. 2499 - 2502 (2008)
A simple heterogeneously palladium-catalysed procedure for the selective C3-arylation of indoles is reported. Under relatively standard reaction conditions (Pd-catalyst, K2CO3, dioxane, reflux), using only 1 mol % [Pd(NH3)4]/NaY as the catalyst, indoles substituted or not at position 2 gave up to 92% conversion (i.e., 85% isolated yield) towards the expected C3-arylated indole.
Cascade radical reactions via α-(arylsulfanyl)imidoyl radicals: Competitive [4 + 2] and [4 + 1] radical annulations of alkynyl isothiocyanates with aryl radicals
Benati, Luisa,Calestani, Gianluca,Leardini, Rino,Minozzi, Matteo,Nanni, Daniele,Spagnolo, Piero,Strazzari, Samantha,Zanardi, Giuseppe
, p. 3454 - 3464 (2003)
Aryl radicals react with 2-(2-phenylethynyl)phenyl isothiocyanate through a novel radical cascade reaction entailing formation of α-(arylsulfanyl)imidoyl radicals and affording a new class of compounds, i.e. thiochromeno[2,3-b]indoles. These derivatives are formed as mixtures of substituted analogues arising from competitive [4 + 2] and [4 + 1] radical annulations. The isomer ratio is strongly dependent on the aryl substituent and is correlated to its capability to delocalize spin density. The presence of a methylsulfanyl group in the ortho-position of the initial aryl radical results in complete regioselectivity and better yields, as the consequence of both strong spindelocalization effect, which promotes exclusive [4 + 1] annulation, and good radical leaving-group ability, which facilitates aromatization of the final cyclohexadienyl radical. Theoretical calculations support the hypothesis of competitive, independent [4 + 2] and [4 + 1] annulation pathways. They also suggest that rearrangement onto the sulfur atom of the [4 + 1] intermediate does not occur via a sulfuranyl radical but rather through either a transition state or a sulfur-centered (thioamidyl) radical; the latter is possibly the preferred route in the presence of an o-methylsulfanyl moiety that can act as a leaving group in the final ipso-cyclization process.
Transition-metal-free, visible-light induced cyclization of arylsulfonyl chlorides with o-azidoarylalkynes: a regiospecific route to unsymmetrical 2,3-disubstituted indoles
Gu, Lijun,Jin, Cheng,Wang, Wei,He, Yonghui,Yang, Guangyu,Li, Ganpeng
supporting information, p. 4203 - 4206 (2017/04/21)
A visible-light-catalyzed synthesis of unsymmetrical 2,3-diaryl-substituted indoles from arylsulfonyl chlorides and o-azidoarylalkynes at room temperature has been discovered. This transformation exhibits excellent substrate scope and functional group tolerance. The use of inexpensive eosin Y as the catalyst with easy operation makes this protocol very practical.
Phosphine-free thiopseudourea-Pd(II) complex catalyzed Larock heteroannulation of 2-haloamines with internal alkynes
Srinivas, Keesara,Saiprathima, Parvathaneni,Balaswamy, Kodicherla,Ra, Mandapati Mohan
, p. 162 - 167 (2013/10/01)
We examined the Pd-catalyzed heteroannulation of 2-haloamines with internal alkynes under phosphinefree conditions. The thiopseudourea palladium(II) complex (5) found to be an efficient catalyst for the Pd induced heteroannulation. Achieved high turnover number for the heteroannulation reactions of internal alkynes with 2-iodoaniline. A variety of 2-bromoanilines and N-tosyl substituted 2-bromoanilines effectively reacted with different substituted internal alkynes to give the corresponding indoles in good to high yields (1:1 ratio of regioisomers).
