Novel Intramolecular Reactivity of Oximes: Synthesis of Cyclic and Spiro-Fused Imines
摘要:
Under conventional heat (135-145 degrees C) or microwave irradiation and 1 equiv of acetic anhydride, ortho-substituted aryl-oximes undergo a novel sp(3) C-H activated cyclization to produce the corresponding isoindoles, and aliphatic oximes afford the corresponding dihydropyrroles. The cyclization occurs with various substrates in good yield (46-82%) leading to unique spiro-fused and cyclic imines. An initial mechanistic investigation suggests the reaction occurs via a nitrenium or vinyl nitrene intermediate.
Ruthenium-Catalyzed Para-Selective Oxidative Cross-Coupling of Arenes and Cycloalkanes
作者:Xiangyu Guo、Chao-Jun Li
DOI:10.1021/ol202081c
日期:2011.10.7
A novel, direct para-selective oxidativecross-coupling of benzene derivatives with cycloalkanes catalyzed by ruthenium was developed. A wide range of arenes bearing electron-withdrawing substituents was functionalized directly with simple cycloalkanes with high para-selectivity; arenes with electron-donating groups were mainly para-functionalized. Benzoic acid can be used directly.
PROCESS OF PRODUCING OXALATE BY CO GAS PHASE METHOD
申请人:Liu Juntao
公开号:US20130197265A1
公开(公告)日:2013-08-01
The present invention relates to a process of producing oxalate by CO gas phase method for chiefly solving the technical problem of the low utilization efficiency of nitrogen oxides or nitrous acid esters in the prior art. The present invention solves the problem in a better way by using the following steps including: a gas phase stream V containing NO and methanol and oxygen enter a supergravity rotating bed reactor II and are subjected to the oxidative esterification reaction to produce an effluent VI containing methyl nitrite; a methyl nitrite effluent VII obtained from separating said effluent VI together with a CO gas II enter a coupling reactor II and is contacted with a catalyst II to react to form a dimethyl oxalate effluent VIII and a gas phase effluent IX containing NO; the resultant dimethyl oxalate effluent VIII is separated to obtain a dimethyl oxalate product I; optionally, the gas phase effluent IX containing NO is returned to the step above so as to be mixed with the gas phase stream V containing NO for being recycled. Therefore, the process is applicable to the industrial production of oxalate by CO gas phase method.
Achieving Site Selectivity in Metal-Catalyzed Electron-Rich Carbene Transfer Reactions from <i>N</i>-Tosylhydrazones
作者:Naijing Su、Tianning Deng、Donald J. Wink、Tom G. Driver
DOI:10.1021/acs.orglett.7b01694
日期:2017.8.4
Catalyst control of the site-selectivity of electron-rich alkyl, aryl disubstituted carbenes generated in situ from o-alkenyl-substituted N-tosylhydrazones was achieved in this study. Exposure of these substrates to copper iodide triggered the formation of α-alkoxy 2H-naphthalenones. This investigation established that changing the catalyst to a rhodium(II) carboxylate turned off cyclization and migration
作者:Gang-Wei Wang、Matthew Wheatley、Marco Simonetti、Diego M. Cannas、Igor Larrosa
DOI:10.1016/j.chempr.2020.04.006
日期:2020.6
meta-selective sp2 C–H alkylation with secondary alkylhalides is well established, ortho selectivity has never been achieved. We demonstrate that the use of a cyclometalated Ru-complex, RuBnN, as the catalyst results in a complete switch of the inherent meta-selectivity to ortho selectivity in the Ru-catalyzed sp2 C–H alkylation reaction with unactivated secondary alkylhalides. The high catalytic activity
Cobalt-Catalyzed Ortho Alkylation of Aromatic Imines with Primary and Secondary Alkyl Halides
作者:Ke Gao、Naohiko Yoshikai
DOI:10.1021/ja403759x
日期:2013.6.26
alkylation of aromatic imines with alkyl chlorides and bromides, which allows the introduction of a variety of primary and secondaryalkyl groups at room temperature. The stereochemical outcomes of the reaction of secondaryalkylhalides suggest that the present reaction involves single-electrontransfer from a cobalt species to the alkylhalide to generate the corresponding alkyl radical. A cycloalkylated