3-(o-Trifluoroacetamidoaryl)-1-propargylic esters: common intermediates for the palladium-catalyzed synthesis of 2-aminomethyl-, 2-vinylic, and 2-alkylindoles
3-(o-Trifluoroacetamidoaryl)-1-propargylic esters have been used as common synthetic intermediates for the preparation of a variety of 3-unsubstituted 2-substituted indoles. Treating ethyl 3-(o-trifluoroacetamidoaryl)-1-propargylic carbonates unsubstituted or containing an aryl substituent at the propargylic carbon with piperazines and Pd(PPh3)4 in THF at 80 °C affords 2-(piperazin-1-ylmethyl)indoles in excellent yields
One-pot access to tetrahydrobenzo[<i>c</i>]carbazoles from simple ketones by using O<sub>2</sub> as an oxidant
作者:Shuvendu Saha、Modhu Sudan Maji
DOI:10.1039/c9ob02751c
日期:——
diversely functionalized carbazole frameworks starting from protecting group free 2-alkenyl indoles. The employment of easily available unactivated ketones as annulating partners, mostly unexplored for the synthesis of carbazoles, is the major highlight of this protocol. This protocol is step- and atom-economical, uses molecular oxygen as the green oxidant, and gives water as the only by-product and is amenable
Brønsted Acid Catalyzed One-Pot Benzannulation of 2-Alkenylindoles under Aerial Oxidation: A Route to Carbazoles and Indolo[2,3-<i>a</i>]carbazole Alkaloids
作者:Shuvendu Saha、Ankush Banerjee、Modhu Sudan Maji
DOI:10.1021/acs.orglett.8b03063
日期:2018.11.2
A one-pot, protecting-group-free benzannulation of 2-alkenylindoles with readily available 1,3-dicarbonyls is demonstrated to construct structurally diverse carbazoles. The use of a cheap Brønsted acid catalyst and air as the sole oxidant exemplifies the economic viability of this protocol. The execution of four different reactions successively to generate the medicinally important indolocarbazole
Indol-2-yltributylstannane: A Versatile Reagent for 2-Substituted Indoles
作者:Sharada S. Labadie、Edmond Teng
DOI:10.1021/jo00094a042
日期:1994.7
A general method for 2-substituted indoles via the palladium-catalyzed coupling of indol-2-ylstannanes is described. (N-Methylindol-2-yl)tributylstannane (1) reacts with a variety of electrophiles under very mild conditions: [N-tert-Butoxycarbonyl)indol-2-yl]tributylstannane (3) is much less reactive in the coupling reactions and reacts only with certain activated electrophiles. [N-[[(Trimethylsilyl)ethoxy]methylindol-2-yl]tributylstannane (4) behaves similarly to 1 and the removal of the [(trimethylsilyl)ethoxy]methyl group can be achieved with tetra-n-butylammonium fluoride in DMF in the presence of ethylenediamine.