AbstractCarbazoles have attracted high interest among synthetic chemists due to their unique structural features and potential pharmacological activities. Compared to linear aryliodoniums, cyclic diphenyleneiodoniums are more inert and have not attracted much attention to their application as building blocks. Employing our synthetic strategy, diversified carbazoles can be efficiently obtained from a single cyclic diphenyleneiodonium under mild conditions. The reactions catalyzed by copper(II) acetate have provided a variety of carbazoles in modest to good yields with a broad range of amines including anilines, aliphatic amines and sulfonamides. Moreover, one of the obtained carbazoles has displayed an outstanding ability to protect HT‐22 neuronal cells from the damage induced by neurotoxins glutamate and homocysteic acid.magnified image
Development of an Air-Stable Nickel Precatalyst for the Amination of Aryl Chlorides, Sulfamates, Mesylates, and Triflates
作者:Nathaniel H. Park、Georgiy Teverovskiy、Stephen L. Buchwald
DOI:10.1021/ol403209k
日期:2014.1.3
A new air-stablenickelprecatalyst for C–Ncross-coupling is reported. The developed catalyst system displays a greatly improved substrate scope for C–N bond formation to include both a wide range of aryl and heteroaryl electrophiles and aryl, heteroaryl, and alkylamines. The catalyst system is also compatible with a weak base, allowing the amination of substrates containing base-sensitive functional
Highly Efficient Ligands for the Palladium-Assisted Double<i>N</i>-Arylation of Primary Amines for One-Sep Construction of Carbazoles
作者:Yibo Zhou、John G. Verkade
DOI:10.1002/adsc.200900846
日期:2010.3.8
highly efficient one‐pot synthesis of carbazoles via palladium‐catalyzed double N‐arylation of primary amines with 2,2′‐dihalobiphenyls is described using a catalyst system comprised of tris(dibenzylideneacetone)dipalladium(0) (Pd2dba3) and the proazaphosphatrane P(i‐BuNCH2CH2)3N (8) or its derivative (t‐Bu)2PNP(i‐BuNCH2CH2)3N (9a) as the ligand. The process is effective for double N‐arylation of 2
under mild conditions (110 °C) in a short period of time (15 min to 2h) to give N‐(hetero)arylcarbazoles in high yields. The reactions of bromochlorobenzenes proceeded in favour of the bromo group to afford N‐(chlorophenyl)carbazoles in a highly selective manner. Functional materials for use in organiclight‐emitting diodes, such as mCP, 26mcPy, CBP and TCB, were also obtained in high yields within 15 min
A Rh(III)-catalyzed C–Hactivation of boronic acid with aryl azide to obtain unsymmetric carbazoles, 1H-indoles, or indolines has been developed. The reaction constructs dual distinct C–N bonds via sp2/sp3 C–Hactivation and rhodium nitrene insertion. Synthetically, this approach represents an access to widely used carbazole derivatives. The practical application to CBP and unsymmetric TCTA derivatives