Catalyst innovation lies at the heart of transition-metal-catalyzed reaction development. In this article, we have explored the C(sp2)–H alkenylation activity with novel spirocyclic N-heterocyclic carbene(NHC)-based ...Catalyst innovation lies at the heart of transition-metal-catalyzed reaction development. In this article, we have explored the C(sp2)–H alkenylation activity with novel spirocyclic N-heterocyclic carbene(NHC)-based cyclometalated ruthenium pincer catalyst system, SNRu-X. After screening catalyst and condition, a high valent Ru(Ⅳ) dioxide(X = O_(2)) species has demonstrated superior reactivity in the catalytic alkenylation of aromatic and olefinic C–H bonds with unactivated alkenyl bromides and triflates. This reaction has achieved the easy construction of a wide range of(hetero)aromatic alkenes and dienes, in good to excellent yields with exclusive selectivity. Preliminary mechanistic studies indicate that this reaction may proceed through a single electron transfer(SET) triggered oxidative addition, by doing so, providing valuable complementary to classical alkenylation reactions that are dependent on activated alkenyl precursors.展开更多
Halogens are elements in soil and water that occur as organic and inorganic species.Studies have shown that inorganic halogens are closely related to animal and plant life.Matrix-assisted laser desorption/ionization m...Halogens are elements in soil and water that occur as organic and inorganic species.Studies have shown that inorganic halogens are closely related to animal and plant life.Matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)can achieve high-throughput and rapid analysis,which is also an essential characteristic in some environmental studies.However,there is currently no report on MALDI-MS analysis for water-soluble inorganic halogen compounds.In this study,we aimed to develop a reliable and reproductive method to detect inorganic halogens in soil and water by MALDI-MS.Based on sinapic acid(SA)and silver trifluoromethanesulfonate(SA/AgOTf)as the matrix in negative-ion mode,MALDI-MS showed excellent MS signals related to halogens.Under the optimum conditions,the method achieved satisfactory linearity(R^(2)>0.99)and repeatability(RSD<18%).The LODs for Cl^(−),Br^(−)and I^(−)were 0.76,0.11 and 0.10μg/mL,respectively.The concentration of inorganic halogens from 24 samples was successfully determined by MALDI-MS.In summary,an innovative method was developed for the analysis of inorganic halogens by MALDI-MS using a novel SA/AgOTf matrix,extending the application of MALDI-MS in inorganic compounds.展开更多
基金suported by the National Natural Science Foundation of China (2187,1117, 91956203)the “111” Program of Minister of Education, Beijing National Laboratory for Molecular Sciences (BNLMS202109)the Science and Technology Commission of Shanghai Municipality (19JC1430100)。
文摘Catalyst innovation lies at the heart of transition-metal-catalyzed reaction development. In this article, we have explored the C(sp2)–H alkenylation activity with novel spirocyclic N-heterocyclic carbene(NHC)-based cyclometalated ruthenium pincer catalyst system, SNRu-X. After screening catalyst and condition, a high valent Ru(Ⅳ) dioxide(X = O_(2)) species has demonstrated superior reactivity in the catalytic alkenylation of aromatic and olefinic C–H bonds with unactivated alkenyl bromides and triflates. This reaction has achieved the easy construction of a wide range of(hetero)aromatic alkenes and dienes, in good to excellent yields with exclusive selectivity. Preliminary mechanistic studies indicate that this reaction may proceed through a single electron transfer(SET) triggered oxidative addition, by doing so, providing valuable complementary to classical alkenylation reactions that are dependent on activated alkenyl precursors.
基金This study was jointly supported by the National Natural Science Foundation of China(21906137)the Science and Technology Program of Zhejiang Province(LGC21B050008).
文摘Halogens are elements in soil and water that occur as organic and inorganic species.Studies have shown that inorganic halogens are closely related to animal and plant life.Matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)can achieve high-throughput and rapid analysis,which is also an essential characteristic in some environmental studies.However,there is currently no report on MALDI-MS analysis for water-soluble inorganic halogen compounds.In this study,we aimed to develop a reliable and reproductive method to detect inorganic halogens in soil and water by MALDI-MS.Based on sinapic acid(SA)and silver trifluoromethanesulfonate(SA/AgOTf)as the matrix in negative-ion mode,MALDI-MS showed excellent MS signals related to halogens.Under the optimum conditions,the method achieved satisfactory linearity(R^(2)>0.99)and repeatability(RSD<18%).The LODs for Cl^(−),Br^(−)and I^(−)were 0.76,0.11 and 0.10μg/mL,respectively.The concentration of inorganic halogens from 24 samples was successfully determined by MALDI-MS.In summary,an innovative method was developed for the analysis of inorganic halogens by MALDI-MS using a novel SA/AgOTf matrix,extending the application of MALDI-MS in inorganic compounds.
