Rhodium-Catalyzed Cascade Annulative Coupling of 3,5-Diarylisoxazoles with Alkynes
作者:Teppei Noguchi、Yuji Nishii、Masahiro Miura
DOI:10.1055/s-0037-1610376
日期:2019.1
the sequential construction of isoquinoline and naphtho[1,8-bc]pyran frameworks connected by a biaryl linkage is achieved by a single operation. Most of the obtained polycyclic compounds exhibit visible fluorescence in both the solution and the solid state. The hexaphenylated isoquinoline-naphthopyran conjugate (R = Ph) as a representative product shows a green emission which can be turned off by making
作为《五十周年综合报告》的一部分发行-黄金周年纪念日 抽象的 在Cu(II)氧化剂存在下,铑催化的3,5-二芳基异恶唑与三当量炔烃的级联环氧化反应平稳进行,其中异喹啉和萘并[1,8- bc ]吡喃骨架的顺序结构相连联芳键的单键操作是通过一次操作即可实现的。大部分获得的多环化合物在溶液和固态下均显示可见的荧光。作为代表产物的六苯基化异喹啉-萘并吡喃共轭物(R = Ph)显示绿色发射,可通过用酸制备异喹啉鎓盐来关闭该发射。通过用碱处理也可逆地开启发射。 在Cu(II)氧化剂存在下,铑催化的3,5-二芳基异恶唑与三当量炔烃的级联环氧化反应平稳进行,其中异喹啉和萘并[1,8- bc ]吡喃骨架的顺序结构相连联芳键的单键操作是通过一次操作即可实现的。大部分获得的多环化合物在溶液和固态下均显示可见的荧光。作为代表产物的六苯基化异喹啉-萘并吡喃共轭物(R = Ph)显示绿色发射,可通过用酸制备异喹啉鎓盐
Ru(<scp>ii</scp>) catalyzed chelation assisted C(sp<sup>2</sup>)–H bond functionalization along with concomitant (4 + 2) annulation
作者:Anindita Sarkar、Moumita Saha、Asish R. Das
DOI:10.1039/d3ob00828b
日期:——
been established to synthesize a structurally privileged Π-extended coumarin-fused pyridone nucleus by activating the vinylic C(sp2)–H bond of coumarin-3-carboxamide under the influence of inexpensive Ru(II)-metal. Here an N-methoxy carboxamide entity has been exploited as the chelating fragment to manifest C(sp2)–H bond functionalization with a concomitant (4 + 2) annulation reaction, resulting in heterocyclic
Isoxazole as a nitrile synthon: <i>en routes</i> to the <i>ortho</i>-alkenylated isoxazole and benzonitrile with allyl sulfone catalyzed by Ru(<scp>ii</scp>)
作者:Pritishree Panigrahi、Subhendu Ghosh、Tamanna Khandelia、Raju Mandal、Bhisma K. Patel
DOI:10.1039/d3cc02996d
日期:——
A Ru(II) catalyzedregioselective Heck-type C–H olefination of isoxazole with unactivated allyl phenyl sulfone is revealed. The solvent DCM offers dual sp2–sp2 C–Hactivation via an N-directed strategy, leading to ortho-olefinated isoxazoles with exclusive E-selectivity. On the other hand, in DCE solvent, isoxazole serves as the nitrile synthon and leads to o-olefinated benzonitrile. At a higher temperature
A tandem protocol for the synthesis of fluorinated isoxazoles has been developed via catalytic intramolecular cyclizations of 2-alkynone O-methyl mimes and ensuing fluorination. The reactions proceed smoothly at room temperature in the presence of 5 mol % of (IPr)AuCl, 5 mol % of AgOTs, 2.5 equiv of Selectfluor, and 2 equiv of NaHCO3. This process features an efficient one-pot cascade route to fluoroisoxazoles with high yields and high selectivity under mild reaction conditions.
Baumstark, Alfons L.; Dunams, Tambra, Journal of Heterocyclic Chemistry, 1981, vol. 18, p. 1113 - 1116