170456-76-5Relevant articles and documents
Cascade Synthesis of 4-Arylcoumarins: Pd-Catalyzed Arylations and Cyclizations with (E)-Ethyl 3-(2-Hydroxyaryl)acrylates and Triarylantimony Difluorides
Kitamura, Yuki,Matsumura, Mio,Kato, Yukari,Murata, Yuki,Yasuike, Shuji
supporting information, p. 1652 - 1657 (2020/03/05)
Herein, we describe a simple general method for the synthesis of 4-arylcoumarins using pentavalent organoantimony compounds. The reactions of 3-(2-hydroxyaryl)acrylates with triarylantimony difluorides in the presence of Pd(OAc)2 (10 mol-%) and 2,2'-bipyridyl (10 mol-%) at 80 °C under aerobic conditions afforded 4-arylcoumarins in good-to-excellent yields. This protocol involves a cascade oxidative Heck-type arylation followed by cyclization, with all the aryl groups in the triarylantimony difluoride transferred to the coupling products. Triarylantimony difluorides resulted in better outcomes than those obtained with other pentavalent organoantimony or bismuth compounds.
Practical Ni-Catalyzed Cross-Coupling of Unsaturated Zinc Pivalates with Unsaturated Nonaflates and Triflates
Hofmayer, Maximilian S.,Lutter, Ferdinand H.,Grokenberger, Lucie,Hammann, Jeffrey M.,Knochel, Paul
, p. 36 - 39 (2019/01/04)
A practical nickel-catalyzed cross-coupling of (hetero)aryl or alkynylzinc pivalates with various unsaturated nonaflates or triflates is described. Organozinc pivalates allow these cross-couplings to take place with high yields and a low catalyst loading (0.5 mol %). Couplings with (E)- and (Z)-alkenyl triflates proceed with retention of configuration.
Formal Carbene Insertion into C?O or C?N Bond: An Efficient Strategy for the Synthesis of 2-Substituted 2H-Chromene Derivatives from Chromene Acetals or Hemiaminal Ethers
Zhang, Dan,Hu, Wenhao
, p. 2446 - 2452 (2018/05/14)
We report the palladium/Br?nsted acid co-catalyzed formal insertion of carbene into the C?O or C?N bond of 2H-chromene acetals or hemiaminal ethers. This transformation was initiated by the Br?nsted acid-promoted cleavage of the C?O or C?N bond, followed by modification of the leaving alcohol or amino fragments with palladium carbenes, and reassembly of the modified fragments. A variety of C-2 functionalized 2H-chromene derivatives were obtained in moderate yield (43～75%) with good to excellent diastereoselectivities (up to >95:5 dr) under mild conditions. (Figure presented.).
