40989-96-6Relevant academic research and scientific papers
Cage-shaped borate esters with enhanced Lewis acidity and catalytic activity
Yasuda, Makoto,Yoshioka, Sachiko,Yamasaki, Satoshi,Somyo, Toshio,Chiba, Kouji,Baba, Akio
, p. 761 - 764 (2006)
A cage shape causes high Lewis acidity and catalytic activity on boron. Borate esters that have cage-shaped ligands have accessible LUMO with lower eigenvalues than normal open-shaped borate esters. A large dihedral angle at C-O-B-O in cage-shaped borate
Tuning Lewis Acidity by a Transannular pπ–σ* Interaction between Boron and Silicon/Germanium Atoms Supported by a Cage-Shaped Framework
Konishi, Akihito,Nakaoka, Koichi,Nakajima, Hideto,Chiba, Kouji,Baba, Akio,Yasuda, Makoto
, p. 5219 - 5223 (2017)
Cage-shaped borates tethered by heavier Group 14 elements (Si or Ge) were synthesized. These possess an intramolecularly transannular pπ–σ* interaction between the boron center and the tethered Si/Ge atom, which allows the precise tuning of their Lewis acidity. The Lewis acidity was investigated by the ligand-exchange reaction rate and IR measurements with the help of theoretical calculation. The synthesized borates exhibited catalytic activity. This study demonstrated the effectiveness of the direct orbital perturbation of a metal center by space interaction during fine tuning of the Lewis acidity.
Use of Organometallic Complexes of Ruthenium in the Lewis Acid Catalyzed Hetero Diels-Alder Reaction
Faller, J. W.,Smart, C. J.
, p. 1189 - 1192 (1989)
The hetero Diels-Alder reaction between benzaldehyde and a functionalized diene can be catalyzed by the Lewis acid transition metal complexes, PF6 (L=L'=PPh3, or LL'=1,2-bis-diphenylphosphinoethane, (-)-DIOP or (S,S)-CHIRAPHOS).
Indium triflate-an efficient catalyst for hetero Diels-Alder reactions
Ali, Tayyeb,Chauhan, Kamlesh K.,Frost, Christopher G.
, p. 5621 - 5624 (1999)
At a loading as low as 0.5 mol% indium triflate has been found to catalyse the hetero Diels-Alder reaction. A three component coupling reaction between aldehydes, amines and Danishefsky's diene to afford tetrahydropyridine derivatives proceeds similarly i
Synthesis and characterization of sterically crowded aryloxides: ‘Mitsubishi’-class of tetrametallic aluminum complexes
Konishi, Akihito,Nakajima, Hideto,Maruyama, Hikaru,Yoshioka, Sachiko,Baba, Akio,Yasuda, Makoto
, p. 130 - 134 (2017)
A new series of tetrameric aluminum molecules with a Mitsubishi structure, composed of two cage-shaped triphenolic ligands with a tripod-chelated structure, have been synthesized and characterized. Transmetalation from the cage-shaped borates was a proper
Thiazolinium salt: an efficient catalyst for the Mukaiyama reaction
Mercey, Guillaume,Brégeon, Delphine,Baudequin, Christine,Guillen, Frédéric,Levillain, Jocelyne,Gulea, Mihaela,Plaquevent, Jean-Christophe,Gaumont, Annie-Claude
, p. 7239 - 7241 (2009)
Mukaiyama aldol reaction between benzaldehyde and Danishefsky diene is promoted by ionic liquid-type salts. Hence, thiazolinium salts have been found to be the most efficient for this transformation. On a mechanistic point of view, only the Mukaiyama proc
Chiral Chromium Salen@rGO as Multipurpose and Recyclable Heterogeneous Catalyst
Abd El Sater, Mariam,Mellah, Mohamed,Dragoe, Diana,Kolodziej, Emilie,Jaber, Nada,Schulz, Emmanuelle
supporting information, p. 9454 - 9460 (2021/05/26)
The first immobilization of a pyrene-tagged chromium salen complex through π-π noncovalent interactions on reduced graphene oxide (rGO) is described. A very robust supported catalytic system is obtained to promote asymmetric catalysis in repeated cycles, without loss of activity or enantioselectivity. This specific behavior was demonstrated in two different catalytic reactions (up to ten reuses) promoted by chromium salen complexes, the cyclohexene oxide ring-opening reaction and the hetero-Diels-Alder cycloaddition between various aldehydes and Danishefsky's diene. Furthermore, the chiral chromium salen@rGO has been found to be compatible with a multi-substrate type use, in which the structure of the substrate involved is modified each time the catalyst is reused.
Selective Activation of Aromatic Aldehydes Promoted by Dispersion Interactions: Steric and Electronic Factors of a π-Pocket within Cage-Shaped Borates for Molecular Recognition
Tanaka, Daiki,Tsutsui, Yuya,Konishi, Akihito,Nakaoka, Koichi,Nakajima, Hideto,Baba, Akio,Chiba, Kouji,Yasuda, Makoto
supporting information, p. 15023 - 15034 (2020/10/20)
Selective bond formations are one of the most important reactions in organic synthesis. In the Lewis acid mediated electrophile reactions of carbonyls, the selective formation of a carbonyl–acid complex plays a critical role in determining selectivity, wh
Synthesis of Cage-Shaped Aluminum Aryloxides: Efficient Lewis Acid Catalyst for Stereoselective Glycosylation Driven by Flexible Shift of Four- To Five-Coordination
Tanaka, Daiki,Kadonaga, Yuichiro,Manabe, Yoshiyuki,Fukase, Koichi,Sasaya, Shota,Maruyama, Hikaru,Nishimura, Sota,Yanagihara, Mayu,Konishi, Akihito,Yasuda, Makoto
supporting information, p. 17466 - 17471 (2019/10/14)
Monomeric cage-shaped aluminum aryl oxides 1Al were synthesized using tripodal triphenolic ligands. The Lewis acidity and catalytic activity of the obtained 1Al·py were investigated. The Lewis acidity of 1Al·py originates from the flexible change in the c
Catalytic asymmetric oxo-Diels-Alder reactions with chiral atropisomeric biphenyl diols
Yeung, Chi-Tung,Chan, Wesley Ting Kwok,Lo, Wai-Sum,Law, Ga-Lai,Wong, Wing-Tak
supporting information, p. 955 - 962 (2019/06/08)
New chiral atropisomeric biphenyl diols 3, 4 and 6 containing additional peripheral chiral centers with different steric bulkiness and/or electronic properties were synthesized. The X-ray crystal structure of 3 shows the formation of a supramolecular stru
