Article
Chemistry, Organic
Mengyu Peng, Mingzhe Li, Longqiang Zhao, Wenxiu Huang, Shoucai Wang, Kang Chen, Guangbin Jiang, Fanghua Ji
Summary: We have developed an electrochemical method for synthesizing 1,3,4-oxadiazole-2(3H)-ones using CO as the carbonyl source. This method features mild, green and oxidant-free conditions, broad substrate scope, short reaction time and ease of scale-up. Control experiments and mechanistic studies confirmed that no radical process was involved in this electrochemical transformation.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Bowen Hu, Haoqiang Zhao, Yu Wu, Patrick J. Walsh
Summary: A novel, selective and high-yielding palladium-catalyzed carbonylative arylation of weakly acidic benzylic and heterobenzylic C(sp(3))-H bonds with aryl bromides has been achieved. The system allows access to diverse alpha-aryl or alpha,alpha-diaryl ketones, which are commonly found in biologically active compounds. The use of Josiphos SL-J001-1-based palladium catalyst enables the carbonylative arylation without the formation of direct coupling byproducts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Dan Wen, Xing Ge, Ren-Guan Miao, Xinxin Qi, Xiao-Feng Wu
Summary: A palladium-catalyzed carbonylative synthesis of carboxamide substituted 2-pynones from methyl enynoates and nitroarenes has been developed. A wide range of carboxamide substituted 2-pynones were obtained in moderate to high yields with quite high functional group compatibility using nitroarenes as the nitrogen sources and Mo(CO)6 as both CO surrogate and reductant. Late-stage modifications of natural molecules were also achieved.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Caijin Zeng, Shaoting Su, Songjia Fang, Huangfeng Jiang, Shaorong Yang, Wanqing Wu
Summary: A novel palladium-catalyzed three-component carbonylation reaction has been developed for the efficient assembly of 1,3-substituted maleimides from haloalkynes and simple anilines. The reaction exhibits high chemo- and regioselectivities, and operates under mild conditions.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Ren Ying, Li Changhua, Wang Tao, Xue Shanshan, Zhang Tingting, Jia Jianfeng, Wu Haishun
Summary: A systematic mechanistic investigation was conducted for the Pd-catalyzed oxidative N-H carbonylation to synthesize 1, 3, 4-oxadiazole-2(3H)-ones. The results showed the preferred catalytic cycle proceeding through N1-H activation, CO insertion, N2-H activation, and reductive elimination, with the rate-determining step being CO insertion. Ligand effect and substituent effect were also elucidated.
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2021)
Article
Chemistry, Multidisciplinary
Yan Zheng, Mengke Dong, Erdong Qu, Jin Bai, Xiao-Feng Wu, Wanfang Li
Summary: A facile synthesis of 4H-benzo[d][1,3]oxazin-4-one derivatives was developed by Pd-catalyzed carbonylative cross-coupling, which does not require toxic and flammable CO gas and tolerates a wide scope of functional groups. Remarkably, this method can be used to construct natural products and drugs containing 4H-benzo[d][1,3]oxazin-4-one structures.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Jian-Shu Wang, Chenyu Li, Jun Ying, Tiefeng Xu, Wangyang Lu, Chuan-Ying Li, Xiao-Feng Wu
Summary: A carbonylative cyclization of 2-bromonitrobenzenes and alkynes catalyzed by palladium supported on graphitic carbon nitride (Pd/g-C3N4) has been developed for the efficient construction of quinolin-4(1H)-one scaffolds using Mo(CO)(6) as the CO surrogate and reductant, and nitroarenes as the nitrogen source.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Applied
Le-Cheng Wang, Yu Zhang, Zhengkai Chen, Xiao-Feng Wu
Summary: A procedure for the palladium-catalyzed carbonylative reaction has been developed for the synthesis of pharmaceutically valuable 2-(trifluoromethyl)quinazolin-4(3H)-ones. The transformation uses Mo(CO)(6) as both a convenient CO source and a reducing reagent. This newly developed protocol is compatible with various nitro compounds and can be readily scaled up to a 1 mmol scale.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Hongjun Li, Dong Tang, Zafar Iqbal, Yaya Wan, Rui Jiang, Zhixiang Yang, Jinhui Yang
Summary: An efficient and eco-friendly synthesis method has been developed for the synthesis of chemically and pharmaceutically interesting compounds, achieving the desired products in good yields through electrochemically promoted access. The method is oxidant-free and transition-metal free, offering electrolyte-free completion of the reaction at room temperature.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Tingzhi Lin, Yan-En Wang, Ning Cui, Miaohui Li, Rui Wang, Jiahui Bai, YiRan Fan, Dan Xiong, Fei Xue, Patrick J. Walsh, Jianyou Mao
Summary: A nickel-catalyzed cross-electrophile coupling reaction has been developed to generate a diverse array of ortho-arylated benzamide derivatives. The reaction shows good functional group tolerance and scalability.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Tingzhi Lin, Yan-En Wang, Ning Cui, Miaohui Li, Rui Wang, Jiahui Bai, YiRan Fan, Dan Xiong, Fei Xue, Patrick J. Walsh, Jianyou Mao
Summary: A nickel-catalyzed cross-electrophile coupling reaction between 1,2,3-benzotriazin-4(3H)-ones and aryl bromides has been developed, leading to a diverse array of ortho-arylated benzamide derivatives. The reaction exhibits good functional group tolerance and utilizes the ring opening of benzotriazinones followed by denitrogenation to obtain various benzamide derivatives (29 examples, 42-93% yield). The scalability of this transformation has been demonstrated.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Madasamy Hari Balakrishnan, Popuri Sureshbabu, Ramaraju Korivi, Subramaniyan Mannathan
Summary: A palladium-catalyzed denitrogenative transannulation strategy to synthesize various 3-substituted isocoumarin-1-imine frameworks is described. The reaction demonstrates high regioselectivity and tolerance towards a wide range of functional groups. It is believed that the reaction proceeds via a five-membered palladacycle intermediate, releasing environmentally benign molecular nitrogen as a by-product. The utility of this method is showcased through the one-pot synthesis of biologically relevant 3-substituted isocoumarin scaffolds.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Jin-Bao Peng, Xin-Lian Liu, Lin Li, Xiao-Feng Wu
Summary: Carbonylation is a powerful method for the preparation of carbonylated compounds, and asymmetric carbonylation is a direct approach to constructing chiral compounds. This review summarizes recent achievements in palladium-catalyzed asymmetric carbonylation reactions.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Chemistry, Organic
Dong Xie, Ren-Gui Tian, Xue-Ting Zhang, Shi-Kai Tian
Summary: This study demonstrates the unprecedented use of benzylsulfonyl hydrazides as benzylating agents in the direct C-3 benzylation of quinoxalin-2(1H)-ones. Various benzylsulfonyl hydrazides participated in the reaction, utilizing CuCN as the catalyst and DTBP as the oxidant, resulting in the formation of structurally diverse 3-benzylquinoxalin-2(1H)-ones with moderate to good yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yuya Hu, Rui Sang, Robby Vroemans, Guillaume Mollaert, Rauf Razzaq, Helfried Neumann, Henrik Junge, Robert Franke, Ralf Jackstell, Bert U. W. Maes, Matthias Beller
Summary: In this study, a straightforward and efficient method for the selective synthesis of diesters using palladium-catalyzed direct carbonylation of di- or polyols with readily available alkenes was presented. The use of a specific palladium catalyst with the built-in-base ligand L16 allowed for esterification of all alcohols and a high n/iso ratio. The synthesized diesters were evaluated as potential plasticizers in PVC films through the measurement of the glass transition temperature (T-g) using differential scanning calorimetry (DSC).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Analytical
Roman Picazo-Frutos, Quentin Stern, John W. Blanchard, Olivier Cala, Morgan Ceillier, Samuel F. Cousin, James Eills, Stuart J. Elliott, Sami Jannin, Dmitry Budker
Summary: Zero- to ultralow-field nuclear magnetic resonance is a magnetic resonance experiment that does not require strong superconducting magnets. It allows high-resolution detection of nuclear magnetism through metal and within heterogeneous media. By using dissolution dynamic nuclear polarization, signals in zero-field nuclear magnetic resonance experiments can be enhanced on sample mixtures, and this technique can be applied to a wide range of molecules. The signal enhancements can reach up to 11,000 compared to thermal prepolarization in a 2 T permanent magnet. The relaxation effects of the TEMPOL radicals used in the hyperpolarization process at zero- and ultralow-fields are also investigated to further increase the signal in future experiments.
ANALYTICAL CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
James Eills, Dmitry Budker, Silvia Cavagnero, Eduard Y. Chekmenev, Stuart J. Elliott, Sami Jannin, Anne Lesage, Joerg Matysik, Thomas Meersmann, Thomas Prisner, Jeffrey A. Reimer, Hanming Yang, Igor V. Koptyug
Summary: Magnetic resonance techniques, especially medical magnetic resonance imaging, are widely used in various scientific disciplines and practical applications. The development of spin hyperpolarization has greatly boosted both fundamental and applied magnetic resonance. Hyperpolarization techniques significantly enhance the signal intensity of magnetic resonance, overcoming its low sensitivity and opening up new possibilities for applications.
Article
Chemistry, Organic
Xi Zhao, Xiaofeng Yu, Mingjun Liu, Yanping Huo, Shaomin Ji, Xianwei Li, Qian Chen
Summary: An efficient synthesis of 9-benzylated fluorenols with high atom economy (<= 91% yield) has been achieved through an external photocatalyst-free benzylic C-H functional-ization using fluorenones under visible-light irradiation. Spectroscopic studies suggest that the photoexcited fluorenones undergo a reductive quenching with toluene derivatives to generate ketyl radicals and benzyl radicals, which then undergo a cross-coupling reaction to yield the desired fluorenols.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Bairong Liu, Yabo Chen, Qixin Liang, Yuyao Liang, Bifu Liu, Yuan Liu, Yang Gao, Qian Chen, Yanping Huo, Xianwei Li
Summary: Regiodivergent [3+2] and [4+2] C-H annulation of imines and imidate esters with unsymmetrical alkynes has been achieved under Rh(III) catalysis. Further transformation of the aldehyde and TMS functionality on the indene products is also demonstrated. The current work highlights the alcohols-directed multiple C-H annulation of imines and imidate esters, leading to diverse fused heterocycles.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Physics, Multidisciplinary
Kai Wei, Tian Zhao, Xiujie Fang, Zitong Xu, Chang Liu, Qian Cao, Arne Wickenbrock, Yanhui Hu, Wei Ji, Jiancheng Fang, Dmitry Budker
Summary: Achieving high energy resolution in spin systems is important for fundamental physics research and precision measurements. We found a new relaxation mechanism in alkali-noble-gas comagnetometers and demonstrated a tenfold increase in nuclear spin hyperpolarization and coherence time with optimal hybrid optical pumping. Our proposed use of this comagnetometer can surpass previous limits in searching for exotic spin-dependent interactions.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Rui Zhang, Dimitra Kanta, Arne Wickenbrock, Hong Guo, Dmitry Budker
Summary: We present an alignment-based 87Rb magnetometer that overcomes the issue of nonlinear Zeeman splitting in alkali-metal atomic magnetometry. The magnetometer exhibits immunity to NLZ-related errors due to a single magnetic resonance peak and well-separated hyperfine transition frequencies. Experimental results show that the magnetometer can be used for practical measurements in geomagnetic environments, achieving a photon-shot-noise-limited sensitivity of 9 fT/pat 5 mu T and remaining stable at tens of fT/ ffiffiffiffiffiffiffiffiffiffiHz p at Hz 50 mu T at room temperature.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Xue Zhang, Abhishek Banerjee, Mahapan Leyser, Gilad Perez, Stephan Schiller, Dmitry Budker, Dionysios Antypas
Summary: The effects of scalar and pseudoscalar ultralight bosonic dark matter were investigated using quartz oscillator frequencies and atomic transitions. Linear interactions were constrained for scalar dark matter in the mass range of 1 x 10-17-8.3 x 10-13 eV, and quadratic interactions were constrained for pseudoscalar dark matter in the mass range of 5 x 10-18-4.1 x 10-13 eV. These constraints improve upon previous direct searches and astrophysical observations.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Atomic, Molecular & Chemical
Danila A. Barskiy, John W. Blanchard, Dmitry Budker, Quentin Stern, James Eills, Stuart J. Elliott, Roman Picazo-Frutos, Antoine Garcon, Sami Jannin, Igor V. Koptyug
Summary: The combination of nuclear hyperpolarization technique with (near-)zero-field modalities has great potential in various applications of nuclear magnetic resonance spectroscopy and imaging, such as biomedical diagnostics and monitoring catalytic reactions in metal reactors.
APPLIED MAGNETIC RESONANCE
(2023)
Article
Chemistry, Organic
Yupeng Zhao, Yang Gao, Zhongke Xie, Shuwei Liao, Jiebin Huang, Yanping Huo, Qian Chen, Xianwei Li, Xiao-Qiang Hu
Summary: Different chemoselectivities were observed between phenols and thiophenols in the Tf2O-promoted C3 functionalization of simple anthranils. Phenols and anthranils react to form 3-aryl anthranils via a C-C bond formation, while thiophenols form 3-thio anthranils through a C-S bond formation. Both reactions have a broad substrate scope and tolerate a wide range of functional groups, yielding the corresponding products with specific chemoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Quantum Science & Technology
Jabir Chathanathil, Dmitry Budker, Svetlana A. Malinovskaya
Summary: A chirped-pulse quantum control scheme called C-CARS is proposed for enhancing the vibrational coherence in molecules during coherent anti-Stokes Raman scattering spectroscopy. The scheme involves chirping of the pump, Stokes, and probe pulses in the four-wave mixing process of CARS to satisfy the conditions of adiabatic passage. By utilizing the rotating wave approximation and adiabatic elimination of excited state manifold, the four-level model system is simplified into a "super-effective" two-level system. It is demonstrated that the excitation selectivity of vibrational degrees of freedom can be controlled by adjusting the spectral chirp rate of the pulses. The robustness, spectral selectivity, and adiabatic nature of this method make it advantageous for improving CARS spectroscopy for sensing, imaging, and detection purposes.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Optics
Derek F. Jackson Kimball, Dmitry Budker, Timothy E. Chupp, Andrew A. Geraci, Shimon Kolkowitz, Jaideep T. Singh, Alexander O. Sushkov
Summary: This article surveys the applications of spin-based quantum sensors in measurements probing fundamental physics. Experimental methods and technologies developed for spin-based quantum information science have rapidly advanced, enabling precise control and measurement of spin dynamics. Theories beyond the standard model predict phenomena such as discrete-symmetry-violating electromagnetic moments correlated with particle spins, exotic spin-dependent forces, and coupling of spins to ultralight bosonic dark-matter fields. Spin-based quantum sensors provide a methodology complementary to particle colliders and large-scale particle detectors, offering a way to search for these phenomena and test fundamental physics. The article also highlights areas of technological development that can enhance the sensitivity of spin-based quantum sensors to new physics.
Article
Chemistry, Multidisciplinary
James Eills, Roman Picazo-Frutos, Dudari B. B. Burueva, Larisa M. M. Kovtunova, Marc Azagra, Irene Marco-Rius, Dmitry Budker, Igor V. V. Koptyug
Summary: We demonstrate a catalyst-free approach to produce hyperpolarized [1-C-13]succinate in aqueous solutions, utilizing parahydrogen-induced polarization (PHIP) and a combination of homogeneous and heterogeneous catalytic hydrogenation reactions. A homogeneous ruthenium catalyst and para-enriched hydrogen gas are employed for PHIP to generate hyperpolarized [1-C-13]fumarate, followed by the removal of the toxic catalyst and reaction side products through a purification procedure. A second hydrogenation reaction is carried out using normal hydrogen gas and a solid Pd/Al2O3 catalyst to convert fumarate to succinate. This cost-effective method has a turnover time of a few minutes and represents a significant breakthrough for in vivo applications of hyperpolarized [1-C-13]succinate as a contrast agent.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yuanting Huang, Jinyu Tang, Xi Zhao, Yanping Huo, Yang Gao, Xianwei Li, Qian Chen
Summary: The development of P(O)-heteroatom bond-forming reactions is crucial, but previous methods have limitations. This study presents an efficient and green photocatalytic phosphorylation of heteroatom nucleophiles utilizing acid red 51 as the photocatalyst and air as the oxidant under blue LED irradiation. The reaction exhibits broad substrate scope and provides practical access to phosphinic fluorides, phosphinic amides, phosphoramidates, and phosphinates. Mechanistic studies suggest the involvement of a phosphorus-centered radical cation generated by photocatalytic single electron transfer (SET).
Article
Astronomy & Astrophysics
I. M. Bloch, D. Budker, V. V. Flambaum, I. B. Samsonov, A. O. Sushkov, O. Tretiak
Summary: Scalar-field dark matter models suggest small oscillations of fundamental constants, which could lead to observable variations in the magnetic field of a permanent magnet. We propose an experiment using a SQUID magnetometer or a low-noise radiofrequency amplifier to detect this type of dark matter. Our results show that this experiment may have comparable sensitivity to leading experiments searching for variations of fundamental constants in a frequency range from a few Hz to about 1 MHz. We also discuss the applicability of using variations of fundamental constants to account for the interaction with scalar dark matter.
Article
Chemistry, Organic
Bairong Liu, Jianhang Rao, Weibing Liu, Yang Gao, Yanping Huo, Qian Chen, Xianwei Li
Summary: By tuning the divergent oxidative Heck reaction with O-2 enabled by self-assembled imines, olefins achieved site selectivity and stereoselectivity. The compatibility of strongly coordinating pyridines and quinolines facilitated the concise delivery of selective serotonin 4 receptor ligand, topotecan, and irinotecan analogues.
ORGANIC CHEMISTRY FRONTIERS
(2023)
