Synthesis of Highly Substituted Indolines and Indoles via Intramolecular [4 + 2] Cycloaddition of Ynamides and Conjugated Enynes
作者:Joshua R. Dunetz、Rick L. Danheiser
DOI:10.1021/ja051180l
日期:2005.4.1
Ynamides react with conjugated enynes in intramolecular [4 + 2] cycloadditions to afford substituted indolines that undergo oxidation with o-chloranil to furnish the corresponding indoles. The cycloaddition substrates are easily assembled from derivatives of 3-butynylamine by Sonogashira coupling with alkenyl halides followed by copper-catalyzed N-alkynylation with acetylenic bromides. Diynamides participate
The Reaction of Cyclic Carbinol Amides with Triflic Anhydride as a Method to Prepare α-Trifluoromethyl-Sulfonamido Furans
作者:Paitoon Rashatasakhon、Albert Padwa
DOI:10.1021/ol0272388
日期:2003.1.1
[reaction: see text] A novel synthesis of alpha-trifluoromethyl-sulfonamido furans via the reaction of cyclic carbinol amides with triflicanhydride has been developed. The reaction proceeds under very mild conditions with a wide set of representative lactams to provide the alpha-trifluoromethyl-sulfonamido-substituted furan in high yield. Rapid access to a 5-substituted indoline can be achieved by
Pd(II)-Catalyzed Amination of C−H Bonds Using Single-Electron or Two-electron Oxidants
作者:Tian-Sheng Mei、Xisheng Wang、Jin-Quan Yu
DOI:10.1021/ja904709b
日期:2009.8.12
Pd(II)-catalyzed intramolecular amination of arenes is developed using either a one- or two-electron oxidant. The reaction protocol tolerates a wide range of deactivating groups including acetyl, cyano, and nitro groups. This catalytic reaction allows expedient syntheses of broadly useful substituted indolines or indoles.
Triflic Anhydride Mediated Cyclization of 5-Hydroxy-Substituted Pyrrolidinones for the Preparation of α-Trifluoromethylsulfonamido Furans
作者:Albert Padwa、Paitoon Rashatasakhon、Mickea Rose
DOI:10.1021/jo0341970
日期:2003.6.1
(Tf(2)O) in pyridine resulted in the formation of various substituted sulfonamidofurans. The suggested mechanism involves initial formation of an iminium ion which is subsequently transformed into a transient imino triflate. Cyclization of the highly electrophilic imine onto the oxygen atom of the adjacent carbonyl group generates an imino dihydrofuran intermediate. This species reacts further with