BABIPhos Family of Biaryl Dihydrobenzooxaphosphole Ligands for Asymmetric Hydrogenation
作者:Guisheng Li、Olga V. Zatolochnaya、Xiao-Jun Wang、Sonia Rodríguez、Bo Qu、Jean-Nicolas Desrosiers、Hari P. R. Mangunuru、Soumik Biswas、Daniel Rivalti、Shuklendu D. Karyakarte、Joshua D. Sieber、Nelu Grinberg、Ling Wu、Heewon Lee、Nizar Haddad、Daniel R. Fandrick、Nathan K. Yee、Jinhua J. Song、Chris H. Senanayake
DOI:10.1021/acs.orglett.8b00139
日期:2018.4.6
Novel bidentate phosphine ligands BABIPhos featuring a biaryl bis-dihydrobenzooxaphosphole core are presented. Their synthesis was achieved via Pd-catalyzed reductive homocoupling of dihydrobenzooxaphosphole aryl triflates. An efficient route toward various analogues was also established, giving access to phosphines with different electronic and steric properties. The newly obtained ligands demonstrated
Preparation of vinylglycines by thermolysis of homocysteine sulfoxides
作者:Sravan Kumar Patel、Timothy E. Long
DOI:10.1016/j.tetlet.2009.06.082
日期:2009.9
synthesis and efficacy of preparing Cbz-VG-OMe (1) by thermolysis of alkyl and aryl homocysteine sulfoxides were surveyed. This investigation determined that aryl sulfoxide analogs were more effective for the reaction and that the 2-nitrophenyl analog 10f possessed a unique ability to syn eliminate at temperatures as low as 100 °C. The thermolysis of sulfoxide 10f was additionally discovered to occur
Chiral Rhodium Complexes Derived From Electron-Rich Phosphine-Phosphites as Asymmetric Hydrogenation Catalysts
作者:Pablo Etayo、José L. Núñez-Rico、Anton Vidal-Ferran
DOI:10.1021/om200933b
日期:2011.12.26
Two new chiral cationic rhodium(I) complexes derived from electron-rich dicyclohexylphosphine-phosphite ligands were prepared from enantiopure Sharpless epoxy ethers. The best-performing catalyst system, which bears a less bulky methyl ether moiety, exhibited remarkably high enantioselectivity (up to 99% ee) and reactivity (up to >2500 TON) in asymmetric hydrogenation reactions of various functionalized
Continuous-flow thermolysis for the preparation of vinylglycine derivatives
作者:Nicolas Lamborelle、Justine F. Simon、André Luxen、Jean-Christophe M. Monbaliu
DOI:10.1039/c5ob02036k
日期:——
sulfoxide elimination was carried out under continuous-flow conditions in a mesofluidic thermolysis reactor. The design of the reactor enabled accurate control of reaction time and conditions, affording a convenient scale-independent procedure for the production of N,C-protected vinylglycine derivatives. Thermolysis at 270 °C under 1000 psi of pressure in superheated toluene enabled typical daily outputs
顺式亚砜消除在中射流热解反应器的连续流动条件下进行。反应器的设计能够精确控制反应时间和条件,为制备N,C保护的乙烯基甘氨酸衍生物提供了与规模无关的便捷程序。在270°C和1000 psi的压力下在过热的甲苯中进行热解,典型的每日产量为11至46 g / day,具有出色的选择性和ee(> 97%)。根据计算研究,研究了各种竞争反应途径并进行了合理化。
[EN] PREPARATION OF ALKENES BY MILD THERMOLYSIS OF SULFOXIDES<br/>[FR] PRÉPARATION D'ALCÈNES PAR THERMOLYSE DOUCE DE SULFOXYDES