Interrupted Fischer-Indole Intermediates via Oxyarylation of Alkenyl Boronic Acids
作者:Heng-Yen Wang、Laura L. Anderson
DOI:10.1021/ol401416r
日期:2013.7.5
The oxyarylation of alkenylboronicacids with N-arylbenzhydroxamic acids has been achieved under both copper-mediated and copper-catalyzed conditions to provide access to interrupted Fischer-indole intermediates. This transformation is believed to proceed through a copper-promoted C–O bond forming event followed by a [3,3] rearrangement. The scope of the method is described and mechanistic experiments
Reaction of aromatic nitroso compounds with chemical models of ‘thiamine active aldehyde’
作者:Luísa M. Ferreira、M. Manuel B. Marques、Paulo M.C. Glória、Humberto T. Chaves、João-Pedro P. Franco、Isabel Mourato、José-Rafael T. Antunes、Henry S. Rzepa、Ana M. Lobo、Sundaresan Prabhakar
DOI:10.1016/j.tet.2008.06.008
日期:2008.8
Aromaticnitrosocompounds in the presence of base and 2-(α-hydroxyalkyl)-3,4-dimethylthiazolium trifluoromethanesulfonate and related salts furnish in variable yields O- and N-acyl-aryl hydroxylamines and 3,4-dimethylthiazolium trifluoromethanesulfonate. A primary kinetic isotope effect of 4.9, obtained for the appropriate 2α-deuterated thiazolium salt, points to the C2α–H bond cleavage as the rate
Copper-Catalyzed Tandem <i>O</i>-Vinylation of Arylhydroxylamines/[3,3]-Rearrangement/Cyclization: Synthesis of Highly Substituted Indoles and Benzoindoles
arylhydroxylamine using vinyliodonium salts as vinylation reagents to generate a transient O-vinyl-N-arylhydroxylamine that rapidly undergoes a [3,3]-sigmatropic rearrangement and subsequent cyclization/rearomatization to form a substituted indole. A wide range of highly substituted indoles and benzoindoles can be afforded in good yields. This approach is readily scalable, and the scope and application of this process
Herein, we developed a copper‐mediated Chan‐Lam type O‐arylation of arylhydroxylamines with arylboronic acids to generate transient N,O‐diarylhydroxylamines that could rapidly undergo cascade [3,3]‐sigmatropic rearrangement and rearomatization to afford NOBIN (2‐amino‐2′‐hydroxy‐1,1′‐binaphthyl) analogues under mild conditions. The newly synthesized racemic biaryl products can be further resolved by
transition-metal free direct O-arylation of arylhydroxylamines employing diaryliodonium salts as arylation reagents to form transient N,O-diarylhydroxylamines that could subsequently undergo [3,3]-sigmatropic rearrangement and re-aromatization to afford structurally diverse NOBIN analogs in good to excellent yields under mild conditions.