A catalytic enantioselective domino Heck carbonylation reaction of o-iodoacrylanilides with phenylacetylenes or water has been developed using a Pd/(Cu) catalytic system containing a chiral diphosphine ligand L9, furnishing a wide array of chiral β-carbonylated 3,3-disubstituted oxindoles in high yields with up to 99 % ee values.
A New Preparative Route to Substituted Carbazoles by Benzannulation
作者:Stefano Serra、Claudio Fuganti
DOI:10.1055/s-2005-863741
日期:——
A new regioselective pathway to substituted carbazole derivatives is described here. According to this procedure substituted 2-alkoxycarbonyl-4-acetoxy-9-(p-toluenesulfonyl) carbazoles are obtained by treatment of substituted 6-[2-(p-toluenesulfonylamino)-aryl]-3-alkoxycarbonylhex-3-en-5-ynoic acids with acetic anhydride in the presence of sodium acetate. The latter acids are prepared from the easily available substituted o-iodo-anilines by Sonogashira coupling with propargylic alcohol and Wittig reaction as the key steps. The described benzannulation reaction proceeds in regiospecific fashion and a range of substituents are tolerated.
Palladium-Catalyzed Annulations of Strained Cyclic Allenes
作者:Andrew V. Kelleghan、Dominick C. Witkowski、Matthew S. McVeigh、Neil K. Garg
DOI:10.1021/jacs.1c04896
日期:2021.6.30
We report Pd-catalyzed annulations of in situ generated strained cyclic allenes. This methodology employs aryl halides and cyclic allene precursors as the reaction partners in order to generate fused heterocyclic products. The annulation proceeds via the formation of two new bonds and an sp3 center. Moreover, both diastereo- and enantioselective variants of this methodology are validated, with the
Enantioselective aza-Friedel–Crafts reaction of furan with α-ketimino esters induced by a conjugated double hydrogen bond network of chiral bis(phosphoric acid) catalysts
Chiral C2- and C1-symmetric BINOL-derived bis(phosphoric acid) catalysts, which have OP(O)(OH)2/OP(O)(OH)(OR) moieties at the 2,2′-positions, were developed and used for the enantioselective aza-Friedel–Crafts reaction of 2-methoxyfuran with α-ketimino esters for the first time. The intramolecular conjugated double hydrogen bond network is a key to increasing the Brønsted acidity and preventing deactivation
Synthesis of quinol-4-ones and chroman-4-ones via a palladium-catalysed cascade carbonylation–allene insertion
作者:Ronald Grigg、Angela Liu、Duncan Shaw、Selvaratnam Suganthan、Diane E Woodall、Gnanamoly Yoganathan
DOI:10.1016/s0040-4039(00)01176-x
日期:2000.9
Palladium(0)-catalysed termolecular queuing processes involving oxidative addition to aryl iodides followed by low pressure carbonylation, allene insertion and capture of the resulting pi-allyl palladium(II) species by an internal O- or N-nucleophile occur in good yields. One-pot 3-methylene chromanone/quinolone synthesis-Michael addition-stereoselective reduction are also reported. (C) 2000 Elsevier Science Ltd. All rights reserved.