Recruitment of PostDoc

2-3 Postdoctoral positions are available immediately in the Prof. Liu’s lab. Interested candidates with strong experimental experience on organic chemisty, especially on radical chemistry and transition metal catalysis, please submit a cover letter, Curriculum Vitae (including 2x references) and a short research summary to Prof. Liu, gliu@mail.sioc.ac.cn. Please put "Applications - Liu Group - PostDoc" in the subject line.

Copper-Catalyzed Highly Efficient and Asymmetric Allylic C–H Oxidation of 3-Aryl-Substituted Terminal Alkenes

We disclosed a copper-catalyzed approach for the enantioselective allylic C(sp3)–H oxidation of terminal alkenes, facilitated by introducing a sterically bulky B2Im(C6F5)6 anion. Notably, a wide range of aryl-substituted terminal alkenes were used as limiting reagents, delivering various products with excellent enantioselectivity and regioselectivity (up to 99% ee, >20:1 b/l). Mechanistically, the bulky counteranion was found to be essential for achieving excellent enantioselective control and high catalytic efficiency. This result is published in JACS. Congratulations Yibo.

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Mechanistic Insights into Copper-Catalyzed Asymmetric Cyanation of Allylic C–H Bonds

Direct C–H bond functionalization has emerged as one of the most powerful and practical strategies for the modification of drug molecules. We have recently disclosed a Cu/NFAS (NFAS = N-fluoroalkyl sufonamide) catalytic system that exhibits high site-, regio-, and enantioselectivity for the direct cyanation of allylic C–H bonds. Here, we present a mechanistic investigation of this catalyst system, including the elucidation of side reactions involved in the transformation. This work focuses on an in-depth analysis of the catalytic cycle based on kinetic studies by NMR spectroscopy and characterization of the catalyst speciation by EPR and UV–vis spectroscopy. These studies indicate that a fraction of NFAS is sacrificed to the side reactions of the Cu(II)-bounded N-centered radical (Cu(II)–NCR) species for the generation of silylated sulfonamides and (CN)2. The data also show a great dependence of the reaction yield and selectivity (hydrogen atom abstraction or HAA over side reactions) on the structure of the Cu(II)–NCR species. Kinetic studies and DFT calculations further reveal that oxidation of the CuCN species by NFAS, HAA process, and cyanation of Cu(II)–NCRs with TMSCN have comparable energy barriers, which collectively determine the rate of the overall C–H cyanation reaction. This result is published in JACS. Congratulations Jiayuan Li.

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Site- and enantioselective allylic and propargylic C–H oxidation enabled by copper-based biomimetic catalysis


Methods for direct enantioselective oxidation of C(sp3)–H bonds will revolutionize the preparation of chiral alcohols and their derivatives. We present a copper-based biomimetic catalytic system that achieves highly efficient asymmetric sp3 C–H oxidation with C–H substrates as the limiting reagent. A Cu(II)-bound tert-butoxy radical is responsible for the site-selective C–H bond cleavage,  which resembles the active site of copper-based enzymes for C–H oxidation. The developed method has been successfully accomplished with good  functional group compatibility and exceptionally high site- and enantioselectivity, which is applicable for the late-stage oxidation of  bioactive compounds. This result is published in Nat. Catal. Congratulations Honggang Zhang.

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State Key Laboratory of Organometallic Chemistry

Shanghai Institute of Organic Chemistry, CAS

345 Lingling Lu, 200032 Shanghai, China

Office: Room 1305, Junmou Building

Phone: (+86) 021-54925346

Email: gliu@mail.sioc.ac.cn

Recruitment

Postdoctoral positions are available immediately in the Prof. Liu’s lab. Interested candidates with strong experimental experience on organic chemisty, especially on radical chemistry and transition metal catalysis, please submit a cover letter, Curriculum Vitae (including 2x references) and a short research summary to Prof. Liu, gliu@mail.sioc.ac.cn. Please put "Applications - Liu Group - PostDoc" in the subject line.