cycloadditionfuransfused-ring systemsThe (4+3) cycloaddition reaction between a conjugated diene and an allylic cation constitutes a convenient and conceptually straightforward method to prepare seven-membered rings. in recent years, investigations into this type of cycloaddition, including a number of ...
【4+2】一Cycloaddition:AStrategy 2013,42(3),902-923. Advancesof [5]Hashimoto,T.;Maruoka,K.RecentCatalyticAsymmetric 1,3-Dipolar Alternativefor 【6]Xu,X.;Doyle,M.P.The[3+3]-CycloadditionHeterocycle GeneratedMetalloenolcarbenesas Syntheses:CatalyticallyDipolarAdducts[J]. Acc.Chem.Res.2014,47(4...
A terpene cyclase subsequently catalyses a fragmentation into two reactive intermediates, followed by hydrogen transfers between them and recombination of the fragments by [4 + 3] cycloaddition. This study solves the intricate mechanistic problem of extra methyl group formation in sodorifen ...
Biginelli compounds containing 3,4-dihydropyrimidines and octahydroquinazolinones were conveniently synthesized by this catalyzed protocol from the cycloaddition of aromatic aldehydes with the 1,3-dicarbonyl substrates and urea via ultrasonic waves. The several advantages of the presented approach are high ...
具有给电子性,而烯丙基正离子是缺电子体,具有得电子性.因此呋喃的HOMO和烯丙基正离子的LUMO应该满足前线轨道理论:中的对称性匹配、最大重叠及能量相近3项原则.我们用B3LYP/6—31G得到了各轨道的轨道类型、能量及对称性.烯丙基正离子共有3O个电子,其l5号轨道是HOMO,16号轨道是LUMO,轨道能E:一992.50kJ·mol-...
The Royal Society of ChemistryChemical CommunicationsKinetic resolution of 1-(1-alkynyl)cyclopropyl ketones by gold( I )-catalyzed asymmetric [4+3]cycloaddition with nitrones: scope, mechanism and applications. Yanqing Zhang,Junliang Zhang... Y Zhang,J Zhang - 《Chemical Communications》 被引量: ...
The rate constants of the (4+2)-cycloaddition reaction between substituted E-arenediazocyanides and 2,3-dimethyl-1,3-butadiene have been determined in several solvents. The reaction displays linear Hammett behavior; the data suggest a concerted reaction mechanism.DOI...
近日,中国海洋大学医药学院分子合成中心的徐涛教授团队关于Type II [4+4]型高张力桥环构建的研究成果,以“Regioselective activation of benzocyclobutenones and dienamides lead to anti-Bredt bridged-ring systems by a [4+4] cycloaddition”为题,发表于Nature系列学术期刊《Nature Communications》(《自然·通讯...
A study, involving kinetic measurements on the stopped-flow and conventional UV/Vis timescales, ESI-MS, NMR spectroscopy and DFT calculations, has been carried out to understand the mechanism of the reaction of [Mo3S4(acac)3(py)3][PF6] ([ 1]PF6; acac=acetylacetonate,...
To shed light on the mechanism of the developed cycloadditions using FCBs as the C4 synthon, control experiments of metal complexes with FCB1bwere conducted in deuterated solvent to investigate C–C bond activation process (Fig.7). The reaction of1bin the presence of Rh(COD)2BF4(1.0 equiv....