Umpolung reactions of C=X bonds(X=O,N)are valuable ways of constructing new C–C bonds,which are sometimes difficult to be constructed using traditional synthetic pathways.Classical polarity inversion of C=X bonds(X=O...Umpolung reactions of C=X bonds(X=O,N)are valuable ways of constructing new C–C bonds,which are sometimes difficult to be constructed using traditional synthetic pathways.Classical polarity inversion of C=X bonds(X=O,N)usually requires air or moisture‐sensitive and strong reducing agents,which limit the feasibility of substrate scope.Herein we describe a photo‐induced reductive cross‐coupling reaction of aldehydes,ketones and imines with electron‐deficient arenes(aromatic nitriles)using fac‐Ir(ppy)3as a photocatalyst and diisopropylethylamine(DIPEA)as a terminal reductant under visible light irradiation.Mild conditions and high yields mean that this new polarity inversion strategy can be used with aryl‐substituted alcohols and amines.Spectroscopic studies and control experiments have demonstrated the oxidative quenching of Ir(ppy)3*by electron‐deficient arenes involved in the key step for the C–C bond formation.展开更多
An accurate theoretical study on the MgH radical is reported by adopting the high-level relativistic MRCI+Q method with a quintuple-zeta quality basis set. The reliable potential energy curves of the five A-S states ...An accurate theoretical study on the MgH radical is reported by adopting the high-level relativistic MRCI+Q method with a quintuple-zeta quality basis set. The reliable potential energy curves of the five A-S states of MgH are derived. Then the associated spectroscopic parameters are determined and found to be in good accordance with the available experimental results. The permanent dipole moments (PDMs) and the spin-orbit (SO) matrix elements of A-S states are computed. The results show that the abrupt changes of PDMs and SO matrix elements are attributed to the variations of electronic configurations at the avoided crossing point. The SOC effect leads to the five A-S states split into ten Ω states and results in the double potential well of (2)1//2 state. Finally, the transition properties from the (2)1//2, (1)3//2 and (3)1//2 states to the ground state X2∑+1//2 transitions are obtained, including the transition dipole moments, Franck-Condon factors and radiative lifetimes.展开更多
The synthesis and modification of peptides occupy a unique position in the field of drug development,and the functionalization of amino acids is a valuable strategy as an alternative to peptide modification.Currently,...The synthesis and modification of peptides occupy a unique position in the field of drug development,and the functionalization of amino acids is a valuable strategy as an alternative to peptide modification.Currently,the development of tyrosine(Tyr)as a target amino acid is a major challenge in the field of chemistry.Herein,we report an electrochemical radical coupling reaction of labeling tyrosine-containing active drugs and peptides with thiocarbamate derivatives for the first time.This tri-component,onepot reaction can be performed smoothly under simple,gentle,and clean electrochemical conditions and is suitable for the functionalization of various Tyr-containing drug molecular derivatives and peptides.展开更多
Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long b...Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long been an important endeavor.Herein,we report a NiH-catalyzed reductive hydroalkylation and hydroarylation of enol esters and ethers.α-Oxoalkyl organonickel species were generated in situ in a catalytic mode and then participated in cross-coupling with alkyl or aryl halides.This approach enabled C(sp^(3))–C(sp^(3))and C(sp^(3))–C(sp^(2))bond formation under mild reductive conditions with simple operations,thereby boosting a broad substrate scope and good functional compatibility.Esters of enantioenriched dialkyl carbinols were accessed in a catalytic asymmetric version.Mechanistic studies demonstrated that this reaction proceeded through a syn-addition of Ni–H intermediate to an enol ester with high regio-and enantioselectivity.展开更多
文摘Umpolung reactions of C=X bonds(X=O,N)are valuable ways of constructing new C–C bonds,which are sometimes difficult to be constructed using traditional synthetic pathways.Classical polarity inversion of C=X bonds(X=O,N)usually requires air or moisture‐sensitive and strong reducing agents,which limit the feasibility of substrate scope.Herein we describe a photo‐induced reductive cross‐coupling reaction of aldehydes,ketones and imines with electron‐deficient arenes(aromatic nitriles)using fac‐Ir(ppy)3as a photocatalyst and diisopropylethylamine(DIPEA)as a terminal reductant under visible light irradiation.Mild conditions and high yields mean that this new polarity inversion strategy can be used with aryl‐substituted alcohols and amines.Spectroscopic studies and control experiments have demonstrated the oxidative quenching of Ir(ppy)3*by electron‐deficient arenes involved in the key step for the C–C bond formation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11564019,11574114,11147158,91221301 and 11264020the Natural Science Foundation of Jilin Province under Grant No 20150101003JC
文摘An accurate theoretical study on the MgH radical is reported by adopting the high-level relativistic MRCI+Q method with a quintuple-zeta quality basis set. The reliable potential energy curves of the five A-S states of MgH are derived. Then the associated spectroscopic parameters are determined and found to be in good accordance with the available experimental results. The permanent dipole moments (PDMs) and the spin-orbit (SO) matrix elements of A-S states are computed. The results show that the abrupt changes of PDMs and SO matrix elements are attributed to the variations of electronic configurations at the avoided crossing point. The SOC effect leads to the five A-S states split into ten Ω states and results in the double potential well of (2)1//2 state. Finally, the transition properties from the (2)1//2, (1)3//2 and (3)1//2 states to the ground state X2∑+1//2 transitions are obtained, including the transition dipole moments, Franck-Condon factors and radiative lifetimes.
基金supported by the Guangxi Science and Technology Base and Talent Project(High level Innovative Talents and Team Training)(Guike AD23026094)the Guangxi Natural Science Foundation of China(2021GXNSFFA220005)+1 种基金the National Natural Science Foundation of China(22161008,22061003)the Innovation and Entrepreneurship Training Programme for University Students(202310602013)。
文摘The synthesis and modification of peptides occupy a unique position in the field of drug development,and the functionalization of amino acids is a valuable strategy as an alternative to peptide modification.Currently,the development of tyrosine(Tyr)as a target amino acid is a major challenge in the field of chemistry.Herein,we report an electrochemical radical coupling reaction of labeling tyrosine-containing active drugs and peptides with thiocarbamate derivatives for the first time.This tri-component,onepot reaction can be performed smoothly under simple,gentle,and clean electrochemical conditions and is suitable for the functionalization of various Tyr-containing drug molecular derivatives and peptides.
基金the National Natural Science Foundation of China(grant nos.21732006,51821006,21927814,and 51961135104)the Strategic Priority Research Program of CAS(grant nos.XDB20000000 and XDB37040000)+1 种基金the USTC Research Funds of the Double First-Class Initiative(grant no.YD3530002002)the Users with Excellence Program of Hefei Science Center CAS(grant nos.2019HSCUE017 and 2019HSC-UE005).
文摘Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long been an important endeavor.Herein,we report a NiH-catalyzed reductive hydroalkylation and hydroarylation of enol esters and ethers.α-Oxoalkyl organonickel species were generated in situ in a catalytic mode and then participated in cross-coupling with alkyl or aryl halides.This approach enabled C(sp^(3))–C(sp^(3))and C(sp^(3))–C(sp^(2))bond formation under mild reductive conditions with simple operations,thereby boosting a broad substrate scope and good functional compatibility.Esters of enantioenriched dialkyl carbinols were accessed in a catalytic asymmetric version.Mechanistic studies demonstrated that this reaction proceeded through a syn-addition of Ni–H intermediate to an enol ester with high regio-and enantioselectivity.