On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited ...On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited success.Herein,we report the synthesis and on-surface reactions of 2,7-dibromo-9,9′-bianthryl as the precursor towardπ-extended ZGNRs.Characterization by scanning tunneling microscopy and high-resolution noncontact atomic force microscopy clearly demonstrated the formation of anthracene-fused ZGNRs.Unique skeletal rearrangements were also observed,which could be explained by intramolecular Diels-Alder cycloaddition.Theoretical calculations of the electronic properties of the anthracene-fused ZGNRs revealed spin-polarized edge-states and a narrow bandgap of 0.20 eV.展开更多
We have successfully synthesized 1-(2-phenyl)cyclopropyl-2,3-epoxypropan-1-ol 3, which will be applied to the kinetics study of oxiranylcarbinyl radical.
An efficient synthetic route to muurolane type sesquiterpenes starting from （R）-carvone, employing allylic diazene rearrangement and the ring closing methesis （RCM） reaction as key steps, is described. The first a...An efficient synthetic route to muurolane type sesquiterpenes starting from （R）-carvone, employing allylic diazene rearrangement and the ring closing methesis （RCM） reaction as key steps, is described. The first asymmetric total synthesis of （-）-10α- hydroxy-4-muurolen-3-one 11 and （-）-10β-hydroxy-4-muurolen-3-one C was accomplished. Through the total synthesis, the absolute configurations of the natural products A, B and C were established.展开更多
Described here is a divergent,biosynthetically inspired synthesis of cochlearol B and ganocin A.Key steps of the synthesis include the chromene unit construction through a biomimetic acid-catalyzed[4+2]ring cyclizatio...Described here is a divergent,biosynthetically inspired synthesis of cochlearol B and ganocin A.Key steps of the synthesis include the chromene unit construction through a biomimetic acid-catalyzed[4+2]ring cyclization.A photochemical[2+2]cycloaddition was featured to construct the cyclobutane core of cochlearol B.Different skeletal rearrangements of cochlearol B afforded ganocin A,that one of them was Lewis acid mediated epoxide rearrangement and another was DDQ induced cyclobutane formed tetrahydrofuran ring.The described syntheses not only achieved these natural products in an efficient manner,but also provided insight into the biosynthetic relationship between the two different skeletons.展开更多
The study toward the total synthesis of （R）-（＋）-harmicine is reported in this paper. The enantioselective syn- thesis of pyrrolidinone, the main backbone of of （R）-（＋）-harmicine, has been completed by the me...The study toward the total synthesis of （R）-（＋）-harmicine is reported in this paper. The enantioselective syn- thesis of pyrrolidinone, the main backbone of of （R）-（＋）-harmicine, has been completed by the methodology based on photo-induced Wolff rearrangement of α-diazo-β-carbonyl compounds.展开更多
基金This work was supported by the Swiss National Science Foundation(Grant No.200020_212875)the NCCR MAR-VEL funded by the Swiss National Science Foundation(Grant No.205602)the Werner Siemens Foundation,the Max Planck Society,and the Okinawa Institute of Science and Technology Graduate University.K.M.acknowledges a fellowship from Gutenberg Research College,Johannes Gutenberg University Mainz.Computational support from the Swiss Supercomputing Center(CSCS)under project ID s1141 is gratefully acknowl-edged.We acknowledge PRACE for awarding access to the Fenix Infrastructure resources at CSCS,which are partially funded by the European Union’s Horizon 2020 research and innovation program through the ICEI project under grant agreement No.800858.Technical support from Lukas Rotach is gratefully acknowledged.
文摘On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited success.Herein,we report the synthesis and on-surface reactions of 2,7-dibromo-9,9′-bianthryl as the precursor towardπ-extended ZGNRs.Characterization by scanning tunneling microscopy and high-resolution noncontact atomic force microscopy clearly demonstrated the formation of anthracene-fused ZGNRs.Unique skeletal rearrangements were also observed,which could be explained by intramolecular Diels-Alder cycloaddition.Theoretical calculations of the electronic properties of the anthracene-fused ZGNRs revealed spin-polarized edge-states and a narrow bandgap of 0.20 eV.
文摘We have successfully synthesized 1-(2-phenyl)cyclopropyl-2,3-epoxypropan-1-ol 3, which will be applied to the kinetics study of oxiranylcarbinyl radical.
基金the financial supports from the National Natural Science Foundation of China (No.20272021).
文摘An efficient synthetic route to muurolane type sesquiterpenes starting from （R）-carvone, employing allylic diazene rearrangement and the ring closing methesis （RCM） reaction as key steps, is described. The first asymmetric total synthesis of （-）-10α- hydroxy-4-muurolen-3-one 11 and （-）-10β-hydroxy-4-muurolen-3-one C was accomplished. Through the total synthesis, the absolute configurations of the natural products A, B and C were established.
基金supported by the National Natural Science Foundation of China(Nos.U2006204,21772181,U1906212)Taishan Scholar Youth Expert Program in Shandong Province(No.tsqn201812021)+1 种基金the Marine S&T Fund of Shandong Province for the Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM030003)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(No.2021CXLH0012)。
文摘Described here is a divergent,biosynthetically inspired synthesis of cochlearol B and ganocin A.Key steps of the synthesis include the chromene unit construction through a biomimetic acid-catalyzed[4+2]ring cyclization.A photochemical[2+2]cycloaddition was featured to construct the cyclobutane core of cochlearol B.Different skeletal rearrangements of cochlearol B afforded ganocin A,that one of them was Lewis acid mediated epoxide rearrangement and another was DDQ induced cyclobutane formed tetrahydrofuran ring.The described syntheses not only achieved these natural products in an efficient manner,but also provided insight into the biosynthetic relationship between the two different skeletons.
基金The project is supported by the National Natural Science Foundation of China （No. 21072009, 21172005）, National Basic Research Program of China （973 Program, No. 2009CB825300） and the Research Fund for the Doctoral Program of Higher Education （No 20090001120014）.
文摘The study toward the total synthesis of （R）-（＋）-harmicine is reported in this paper. The enantioselective syn- thesis of pyrrolidinone, the main backbone of of （R）-（＋）-harmicine, has been completed by the methodology based on photo-induced Wolff rearrangement of α-diazo-β-carbonyl compounds.
