Article
Chemistry, Organic
Jun-Bin Tang, Jun-Qian Bian, Yu-Shuai Zhang, Yong-Feng Cheng, Han-Tao Wen, Zhang-Long Yu, Zhong-Liang Li, Qiang-Shuai Gu, Guo-Qiang Chen, Xin-Yuan Liu
Summary: A copper-catalyzed highly anti-selective radical 1,2-alkylarylation of terminal alkynes has been established, providing facile access to various stereo-defined trisubstituted alkenes in high yield under mild reaction conditions.
Article
Chemistry, Multidisciplinary
Yang Ye, Jiandong Liu, Bing Xu, Songwei Jiang, Renren Bai, Shijun Li, Tian Xie, Xiang-Yang Ye
Summary: A novel nickel-catalyzed asymmetric 1,2-vinylboration reaction has been developed for the efficient preparation of chiral compounds with high yields and excellent enantioselectivities. The method shows exceptional chemo- and stereoselectivity and has potential applications in the asymmetric modification of structurally complex natural products and pharmaceuticals.
Article
Chemistry, Organic
Tianhao Xu, Xiangbing Zhou, Yuhui Han, Liangwei Zhang, Long Liu, Tianzeng Huang, Chunya Li, Zhi Tang, Shungang Wan, Tieqiao Chen
Summary: A palladium-catalyzed stereo-selective cis-1,2-arylalkynylation of bicyclic alkenes with aryl triflates and terminal alkynes was developed, exhibiting high tolerance towards functional groups and allowing for the modification of bioactive molecules.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Yuan-Yuan Cheng, Ji-Xin Yu, Tao Lei, Hong-Yu Hou, Bin Chen, Chen-Ho Tung, Li-Zhu Wu
Summary: This study presents the first example of 1,2-dicarbonylation of alkenes by photocatalysis, achieving unsymmetric 1,4-dicarbonylation by tuning the reductive and electrophilic ability of the acyl precursor. The metal-free, redox-neutral and regioselective reaction shows great potential in biomolecular and drug molecular derivatization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Lihong Wang, Jiaqiong Sun, Jiuli Xia, Mingrui Li, Lianjin Zhang, Ruiyang Ma, Guangfan Zheng, Qian Zhang
Summary: This paper presents a method for the selective 1,2-dicarbonylation of alkenes using NHCs and photocatalysis as co-catalysts, which allows for the construction of structurally diverse 1,4-diketones.
SCIENCE CHINA-CHEMISTRY
(2022)
Review
Chemistry, Organic
Yasuyuki Ura
Summary: The review summarizes recent progress in Pd-catalyzed anti-Markovnikov oxidation of terminal alkenes to provide terminally oxyfunctionalized organic compounds. Key additives like BQs are highlighted for enhancing the nucleophilic attack of oxygen nucleophiles on terminal alkenes. Various factors affecting the selectivity of the reaction, including steric hindrance of nucleophiles and substrate addition rate, are also discussed.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Stefan Weber, Daniel Zobernig, Berthold Stoeger, Luis F. Veiros, Karl Kirchner
Summary: The Mn-catalyzed hydroboration of terminal alkenes and the 1,2-diboration of terminal alkynes with pinacolborane have been successfully achieved. The most active pre-catalyst is a bench-stable alkyl bisphosphine Mn-I complex. The catalytic process involves migratory insertion of a CO ligand into the Mn-alkyl bond to yield an acyl intermediate, which further undergoes B-H bond cleavage or C-H bond cleavage for alkenes and alkynes, respectively, forming active Mn-I boryl and acetylide catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Bing Tian, Xiang Li, Pinhong Chen, Guosheng Liu
Summary: A novel Pd-II-catalyzed enantioselective oxycarbonylation of alkenes has been established, featuring high reactivity and excellent enantioselective control, as well as simple operation and wide application range.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Chuanqi Hou, Pinhong Chen, Guosheng Liu
Summary: This study reports a palladium-catalyzed Markovnikov hydroalkynylation reaction for the synthesis of branched alkynyl compounds. The reaction shows excellent functional group tolerance, high reaction yields, and good regioselectivity. Moreover, asymmetric hydroalkynylation has been achieved by introducing a chiral ligand.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yuanyuan Ping, Qi Pan, Ya Guo, Yongli Liu, Xiao Li, Minyan Wang, Wangqing Kong
Summary: Switchable selectivity in skeletal rearrangement can be achieved by controlling the migratory aptitude of different groups. Modifying the ligands on the metal catalyst and changing the oxidation states of the metal allow control over the migratory ability. This method enables site-selective activation and reorganization of C-C bonds and has been used for the synthesis of fluorine-containing scaffolds with medicinal relevance.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Yufeng Sun, Jun Guo, Xuzhong Shen, Zhan Lu
Summary: In this study, a method for sequentially catalyzing alkynes with nitrogen and silicon atoms using a cobalt catalyst is presented. The method involves two catalytic cycles with different ligands, and demonstrates high efficiency, simple operation, and excellent functional group tolerance. The study also reveals a phenomenon of ligand relay, where certain ligands can capture metal ions from other ligands.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Yasuyuki Ura
Summary: This paper describes the challenging realization of anti-Markovnikov selectivity in Pd-catalyzed reactions, with key factors including the steric bulkiness of oxygen nucleophiles and electron-deficient cyclic alkenes as additives.
Review
Chemistry, Organic
Taeho Kang, Omar Apolinar, Keary M. Engle
Summary: In this Review, the various strategies, mechanisms, and catalysts that have been applied to achieve enantioinduction in alkene 1,2-DCF are discussed.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Guangying Tan, Mowpriya Das, Ivan Maisuls, Cristian A. Strassert, Frank Glorius
Summary: The rhodium-catalyzed dealkenylative arylation of alkenes with arylboronic compounds provides an unconventional access to bi(hetero)aryls with excellent chemoselectivity. This method enables the cleavage of C(aryl)-C(alkenyl) and C(alkenyl)-C(alkenyl) bonds in various alkenes and 1,3-dienes, leading to the efficient construction of novel organic fluorescent molecules with excellent photophysical properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ryota Isshiki, Miki B. Kurosawa, Kei Muto, Junichiro Yamaguchi
Summary: A Ni-catalyzed aryl sulfide synthesis method was developed using 2-pyridyl sulfide as the sulfide donor, eliminating the need for odorous and toxic thiols. The Ni/dcypt catalyst played a crucial role in the aryl exchange reaction between 2-pyridyl sulfides and aryl electrophiles, with mechanistic studies showing its ability to undergo oxidative additions and ligand exchanges simultaneously.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
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)