9 article(s) from Yoshida, Jun-ichi
Graphical Abstract
Scheme 1: Generation and reaction of cationic species generated by “indirect cation pool” methods.
Figure 1: (a) 1H NMR of N-acyliminium ion C1 in CD2Cl2 at −80 °C (600 MHz). (b) Preferred conformation of C1.
Figure 2: (a) 1H NMR spectrum of C3 in CD2Cl2 at −60 °C (400 MHz). (b) Preferred conformation of C3.
Figure 3: (a) 1H NMR spectrum of C5 in CD2Cl2 at −60 °C (400 MHz). (b) Preferred conformation of C5.
Figure 4: Summary of the conformations of N-acyliminium ions C1–C6.
Figure 5: Stevens’ hypothesis on the tendency of the addition of nucleophiles to N-acyliminium ions. The subs...
Figure 6: A plausible mechanism of the observed diastereoselective reaction of the N-acyliminium ions.
Figure 7: Comparison of ΔG for the pseudo-equatorial and pseudo-axial conformations of C1–C6 at the B3LYP/6-3...
Graphical Abstract
Scheme 1: Synthesis of halohydrins and epoxides through β-haloalkoxysulfonium ions generated by the reaction ...
Scheme 2: Proposed reaction mechanisms for the syntheses of bromohydrin 5a-Br and epoxide 6a.
Scheme 3: Mechanistic study using 18O-DMSO.
Graphical Abstract
Scheme 1: Cobalt-catalysed 1,4-hydrovinylation.
Scheme 2: Electrochemical selenoalkoxylation of 2.
Scheme 3: Electrochemical iodoalkoxylation of 2.
Graphical Abstract
Figure 1: Two synthetic approaches toward the peripherally functionalized dendronized polystyrenes (blue dott...
Figure 2: Preparation of the dendrimer having peripheral bromo groups and their conversion to diarylamino gro...
Figure 3: Preparation of dendronized polystyrenes having peripheral diarylamino groups.
Figure 4: MALDI–TOF MS analysis of the dendronized polystyrene with peripheral bromo groups.
Figure 5: Cyclic voltammograms of dendronized polystyrene 9 (black line), model compound 10 (blue line), and ...
Graphical Abstract
Scheme 1: Direct fluorination using microreactor systems.
Scheme 2: Use of DAST in continuous-flow reactors.
Scheme 3: Flow microreactor synthesis of fluorinated epoxides.
Scheme 4: Highly controlled isomerization of gem-difluoroalkenes.
Scheme 5: Flow system for catalytic aromatic fluorination.
Scheme 6: Continuous-flow reactor for electrophilic aromatic fluorination.
Scheme 7: Examples of [18F]-radiolabeled molecular imaging probes.
Scheme 8: Flow microreactor synthesis of dipeptides.
Scheme 9: Flow synthesis involving SNAr reactions.
Scheme 10: Flow synthesis of fluoroquinolone antibiotics.
Scheme 11: Highly controlled formation of PFPMgBr.
Scheme 12: Selective flow synthesis of photochromic diarylethenes.
Scheme 13: Flow microreactor system for perfluoroalkylation by generation of perfluoroalkyllithiums in the pre...
Scheme 14: Integrated flow microreactor system for perfluoroalkylation by generation of perfluoroalkyllithiums...
Graphical Abstract
Scheme 1: Electrochemical conversion of thioglycosides to glycosyl triflates.
Figure 1: 1H NMR spectrum of glycosyl triflate 2a.
Scheme 2: Triflic acid mediated isomerization of β-glycoside.
Graphical Abstract
Scheme 1: Halogen–lithium exchange of p-bromoanisole followed by reaction with methanol.
Figure 1: Flow microreactor system for halogen–lithium exchange of aryl halide followed by reaction with meth...
Figure 2: Effects of the temperature (T) and the residence time in R1 (tR1) on the yield of anisole in the Br...
Scheme 2: Halogen-lithium exchange of p-bromoanisole followed by oxidative homocoupling with FeCl3.
Figure 3: Integrated flow microreactor system for oxidative homocoupling reaction of aryllithium with FeCl3. ...
Figure 4: Effects of the temperature (T) and the residence time in R2 (tR2) on the yield of 4,4'-dimethoxybip...
Graphical Abstract
Scheme 1: Sequential introduction of two electrophiles onto dibromobiaryls using Br-Li exchange reactions.
Scheme 2: Br-Li exchange reaction of 2,2′-dibromobiphenyl (1) with n-BuLi using a conventional macrobatch rea...
Figure 1: Microflow system for Br-Li exchange reaction of 2,2′-dibromobiphenyl (1). T-shaped micromixer: M1 (...
Figure 2: Effect of temperature and residence time in Br-Li exchange reaction of 2,2′-dibromobiphenyl (1) usi...
Figure 3: A microflow system for sequential introduction of two electrophiles. T-shaped micromixer: M1 (ø = 2...
Scheme 3: Br-Li exchange reaction of 4,4′-dibromobiphenyl (17) with n-BuLi using a conventional macrobatch re...
Figure 4: Microflow system for Br-Li exchange reaction of 4,4′-dibromobiphenyl (17). T-shaped micromixer: M1 ...
Figure 5: Effect of temperature and residence time in Br-Li exchange reaction of 4,4′-dibromobiphenyl (17) us...
Graphical Abstract
Scheme 1: Electrochemical generation of carbocations by oxidative C-C bond dissociation.
Scheme 2: Electrochemical generation and accumulation of organosilicon cation by oxidative Si-Si bond dissoci...
Figure 1: Oxidation potentials (Ed; decomposition potential) of disilanes determined by rotating disk electro...
Figure 2: Optimized structures of radical cations of 1,2-diphenyldisilane and 1,2-bis [o-(2-pyridyl)- phenyl]...
Scheme 3: Electrochemical generation of organosilicon cation 3d.
Figure 3: CSI-MS of organosilicon cation 3d at 0°C.
Figure 4: Optimized structures of organosilicon cation 3d and silyl radical 4d by DFT calculations (B3LYP/LAN...
Scheme 4: Reaction of organosilicon cation 3d with p-tolylmagnesium bromide.