28405-57-4Relevant academic research and scientific papers
Formal Ir-Catalyzed Ligand-Enabled Ortho and Meta Borylation of Aromatic Aldehydes via in Situ-Generated Imines
Bisht, Ranjana,Chattopadhyay, Buddhadeb
supporting information, p. 84 - 87 (2016/01/25)
The ligand-enabled development of ortho and meta C-H borylation of aromatic aldehydes is reported. It was envisaged that while ortho borylation could be achieved using tert-butylamine as the traceless protecting/directing group, meta borylation proceeds via an electrostatic interaction and a secondary interaction between the ligand of the catalyst and the substrate. These ligand-substrate electrostatic interactions and secondary B-N interactions provide an unprecedented controlling factor for meta-selective C-H activation/borylation.
Synthesis of dihydrobenzisoxazoles by the [3 + 2] cycloaddition of arynes and oxaziridines
Kivrak, Arif,Larock, Richard C.
supporting information; experimental part, p. 7381 - 7387 (2011/02/22)
Dihydrobenzisoxazoles are readily prepared in good yields by the [3 + 2] cycloaddition of oxaziridines and arynes. The reaction involves an unusual cleavage of the C-O bond of the oxaziridine and tolerates a variety of substituents on the oxaziridine and the o-(trimethylsilyl)aryl triflate to form aryl-, heteroaryl-, alkyl-, and naphthyl-substituted dihydrobenzisoxazoles. The resulting halogen-substituted dihydrobenzisoxazoles are readily elaborated to more complex products using palladium-catalyzed crossing-coupling processes.
Isoquinoline synthesis via rhodium-catalyzed oxidative cross-coupling/ cyclization of aryl aldimines and alkynes
Guimond, Nicolas,Fagnou, Keith
supporting information; experimental part, p. 12050 - 12051 (2010/01/29)
(Chemical Equation Presented) A general rhodium-catalyzed oxidative coupling reaction between internal alkynes and aryl aldimines is described. This process affords 3,4-disubstituted isoquinolines in good yield and high regioselectivity. Preliminary mechanistic studies suggest that the C-N bond formation arises from the reductive elimination of a rhodium(III) species.
Reactions of N-Chloro-N-alkylbenzylamines with Amines in Acetonitrile. Origin of Steric Effect in Imine-Forming Elimination
Cho, Bong Rae,Suh, Young Wook
, p. 2855 - 2858 (2007/10/02)
Reaction of N-chloro-N-alkylbenzylamines in which the alkyl group is Me, Et, i-Pr, sec-Bu, and t-Bu with MeNH2 and Et2NH in MeCN have been studied kinetically.The eliminations are quantitative and regiospecific, producing only N-benzylidenealkylamines.The relative rates of elimination for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents are 1/0.6/0.4/0.3/0.1 with MeNH2 and 1/0.5/0.3/0.2/0.03 with Et2NH, respectively.Comparison with published data reveals that Charton's value for the imine-forming elimination decreases with the variation of the base-solvent from MeONa-MeOH to MeNH2-MeCN but increases when the base is changed from MeNH2 to Et2NH.For a given base, Hammett ρ and kH/kD values decrease and the ΔH(excit.) and ΔS(excit.) values increase with bulkier alkyl substituents.From these results, the origin of the steric effect in imine-forming elimination is attributed to the repulsive interaction between the alkyl group and the base in the transition state.
Reactions of N-Chlorobenzylalkylamines with Sodium Methoxide in Methanol. Steric Effects in Elimination Reactions
Cho, Bong Rae,Maeng, Jun Ho,Yoon, Jong Chan,Kim, Tae Rin
, p. 4752 - 4756 (2007/10/02)
Reactions of N-chlorobenzylalkylamines in which the alkyl group is Me, Et, i-Pr, t-Bu, and sec-Bu with MeONa-MeOH have been investigated kinetically.The eliminations are quantitative and regiospecific, producing only benzylidenealkylamines.The reactions are first order in base and first order in substrate, and an E2 mechanism is evident.The relative rates of elimination at 25 deg C are 1/0.5/0.3/0.2/0.01 for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents, respectively.The results are attributed to repulsive interaction between the alkyl group and the base in the transition state.Hammett ρ and kH/kD values decreased, but the ΔH(excit.) and ΔS(excit.) values increased with bulkier alkyl substituents.Changes in the transition-state parameters with the substrate steric effect are interpreted with variation in structure of the imine-forming transition states.
