14064-48-3Relevant articles and documents
Stereospecific synthesis of (E)-alkenyl(phenyl)iodonium tetrafluoroborates via zirconium-iodane exchange
Huang, Xian,Xu, Xin-Hua
, p. 3321 - 3322 (1998)
Reaction of vinylzirconium with hypervalent phenyl-iodanes leads to zirconium-iodane exchange in THF at room temperature yielding alkenyl(phenyl)iodonium salts stereoselectively with retention of configuration. Vinyl-iodonium salts are highly effective as the activated species of vinyl iodides. They reacted with RMgBr in the presence of CuI to afford (E)-1,2-disubstituted alkenes.
Heterobimetallic Pd/Mn and Pd/Co complexes as efficient and stereoselective catalysts for sequential Cu-free Sonogashira coupling–alkyne semi-hydrogenation reactions
Baweja, Saral,Clauss, Reike,Gelman, Dmitri,Hey-Hawkins, Evamarie
supporting information, p. 1344 - 1356 (2022/02/03)
A series of heterobimetallic PdII/MII complexes (MII = Mn, Co) were synthesised and tested as precatalysts for sequential Sonogashira coupling–alkyne semi-hydrogenation reactions to form Z-aryl alkenes. The carbometalated heterobimetallic PdII/CoII complex CoPdL3′ demonstrated an apparent cooperative effect compared to the corresponding monometallic counterparts. This compound was identified as a potent single-molecule catalyst for the one-pot Cu-free Sonogashira coupling of aryl bromides with terminal alkynes followed by chemo- and stereoselective semi-hydrogenation of the alkyne intermediate using NH3·BH3 as a hydrogen source. Furthermore, different aromatic substrates have been tested to show the generality of the reaction for the synthesis of Z-alkenes, including biologically active combretastatin A-4. In addition, the homogeneous nature of the catalytically active species was demonstrated.
Pd-Catalyzed Cross-Coupling of Organostibines with Styrenes to Give Unsymmetric (E)-Stilbenes and (1 E,3 E)-1,4-Diarylbuta-1,3-dienes and Fluorescence Properties of the Products
Zhang, Zhao,Zhang, Dejiang,Zhu, Longzhi,Zeng, Dishu,Kambe, Nobuaki,Qiu, Renhua
supporting information, p. 5317 - 5322 (2021/06/28)
A general and effective palladium-catalyzed cross-coupling of organostibines with styrenes to give (E)-olefins was disclosed. By the use of an organostibine reagent, this method can produce unsymmetric (E)-1,2-diarylethylenes and (1E,3E)-1,4-diarylbuta-1,3-dienes in good yields with high E/Z selectivity and good functional group tolerance. Resveratrol and DMU-212 were synthesized in high yield. The protocol can be extended to the synthesis of (1E,3E,5E)-1,6-diphenylhexa-1,3,5-triene in 40% yield. Products 5e, 5f, and 7a showed good photoluminescence quantum yields ranging from 72 to 99%.
Efficient photocatalytic chemoselective and stereoselective C-C bond formation over AuPd@N-rich carbon nitride
Jiang, Heyan,Xu, Jie,Zhang, Sishi,Cheng, Hongmei,Zang, Cuicui,Bian, Fengxia
, p. 219 - 229 (2021/01/28)
Heterogeneous chemoselective or stereoselective C-C coupling reactions remain extremely challenging in traditional organic synthesis. Here, we constructed a AuPd@N-rich carbon nitride (NRCN) photocatalyst through simple ammonia solution heat treatment of carbon nitride and then AuPd NP loading. AuPd@NRCN exhibited extraordinary light color promoted catalytic performance in C-C bond formation under visible light in air. Surprisingly, both high chemoselectivity to unsymmetrical Ullmann biaryl products and satisfactory stereoselectivity to Z-type Heck reaction products could be achieved by changing the light source color. Various substrates exhibited great potential for the economical synthesis of unsymmetrical biaryl products and Z-type olefins. Efficient visible light promoted C-I bond activation accompanied with improved photocatalytic coupling reaction efficiency over AuPd@NRCN was verified firstly by in situ DRIFTS. Considering that the Ullmann cross-coupling reaction is a multi-photon reaction, the improved photocatalytic performance in the Ullmann cross-coupling reaction using a combination of light sources with different colors might be due to the activation of different substrates and/or steps requiring different energies, and the combination of the two energy sources was beneficial for improving the activation efficiency of different substrates and/or steps. The activation of iodobenzene and styrene in the Heck reaction with light was also beneficial to the formation of the stilbene product. The light color promoted chemoselectivity and stereoselectivity are expected to have profound impact on organic synthetic methodology improvement. This journal is
