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Papers by Benjamin Ganchegui
Journal of Molecular Catalysis B Enzymatic, 2009
The biotransformation of compounds containing silicon has recently been a subject of much interes... more The biotransformation of compounds containing silicon has recently been a subject of much interest. In this study, a variety of commercially available serine hydrolases were tested for their ability to catalyse the hydrolysis of the silicon-ether bond in a variety of silyl ethers. The hydrolysis of trimethylethoxysilane in buffer was not found to be accelerated by the presence of trypsin, chymotrypsin, or a variety of other lipase and protease enzymes. Cleavage of a range of alternative silyl ether substrates, including a trimethylsilyl (TMS) ether, by these hydrolases was also not observed, but, interestingly, only two of the enzymes tested were able to cleave a t-butyl ␣,␣,␣-carboxylate that was approximately isosteric with the TMS-protected substrate. This suggests that the cleavage of Si-O bonds by serine hydrolases, such as the cathepsin homolog silicatein-␣, may be in part limited by steric effects, as the reactive centre in the substrate is always, by analogy to C-centred substrates, tertiary, and thus inherently sterically demanding regardless of the putative catalytic competence of the enzymes.
ChemInform, 2001
reactions of organo-metal compounds reactions of organo-metal compounds O 0350 17 -077
Tetrahedron Letters, 2002
Heating secondary benzylic alcohols in molten tetra-n-butyl ammonium bromide with catalytic amoun... more Heating secondary benzylic alcohols in molten tetra-n-butyl ammonium bromide with catalytic amounts of palladium chloride under a gentle flow of argon produced corresponding ketones in good yields. Neither cooxidant nor additive were required, with the added advantage of catalyst and ammonium salt recycling. The dehydrogenation of primary benzylic alcohols was less selective. Such a reaction was ineffective from allylic and saturated alcohols.
Phosphorus, Sulfur, and Silicon and the Related Elements, 2006
ABSTRACT
New Journal of Chemistry, 2004
Carbon-carbon double bonds have been selectively hydrogenated at room temperature in the presence... more Carbon-carbon double bonds have been selectively hydrogenated at room temperature in the presence of benzyloxy groups using an atmospheric pressure of hydrogen, toluene or [bmim]PF 6 as the solvent and palladium nanoparticles stabilized with tetrabutylammonium bromide. The system [bmim]PF 6 /palladium nanoparticles can be recycled without noticeable decrease of activity.
Journal of Organometallic Chemistry, 2001
The Heck coupling of ArX (X =I, Br) with allylic alcohols, carried out at 80 -120°C in molten n-B... more The Heck coupling of ArX (X =I, Br) with allylic alcohols, carried out at 80 -120°C in molten n-Bu 4 NBr using NaHCO 3 as base and PdCl 2 as catalyst without extra ligands, leads to the corresponding b-arylated carbonyl compounds. After extraction of the organic materials with diethyl ether, the ionic layer can be reused directly.
Journal of Organometallic Chemistry, 2003
A novel reaction sequence leading to the synthesis of substituted biphenyls containing a carbonyl... more A novel reaction sequence leading to the synthesis of substituted biphenyls containing a carbonyl group in an aliphatic chain has been achieved in one-pot reaction starting from iodoarenes and allylic alcohols under the catalytic action of palladium and norbornene. The latter is temporarily incorporated into a palladacycle, which directs the reaction towards the selective formation of an aryl Ã/aryl bond. Norbornene spontaneously deinserts to allow the biphenylylpalladium bond thus formed to react in its turn with the allylic alcohol. #
Journal of Molecular Catalysis B: Enzymatic, 2009
The biotransformation of compounds containing silicon has recently been a subject of much interes... more The biotransformation of compounds containing silicon has recently been a subject of much interest. In this study, a variety of commercially available serine hydrolases were tested for their ability to catalyse the hydrolysis of the silicon-ether bond in a variety of silyl ethers. The hydrolysis of trimethylethoxysilane in buffer was not found to be accelerated by the presence of trypsin, chymotrypsin, or a variety of other lipase and protease enzymes. Cleavage of a range of alternative silyl ether substrates, including a trimethylsilyl (TMS) ether, by these hydrolases was also not observed, but, interestingly, only two of the enzymes tested were able to cleave a t-butyl ␣,␣,␣-carboxylate that was approximately isosteric with the TMS-protected substrate. This suggests that the cleavage of Si-O bonds by serine hydrolases, such as the cathepsin homolog silicatein-␣, may be in part limited by steric effects, as the reactive centre in the substrate is always, by analogy to C-centred substrates, tertiary, and thus inherently sterically demanding regardless of the putative catalytic competence of the enzymes.
Journal of Molecular Catalysis A: Chemical, 2004
Saturated ketones have been produced by heating secondary allylic alcohols and catalytic amounts ... more Saturated ketones have been produced by heating secondary allylic alcohols and catalytic amounts of PdCl2 or Pd(OAc)2 in molten n-Bu4NBr. After extraction of the organic material with diethyl ether, the ionic layer and the catalyst can be reused directly. Linear secondary homoallylic alcohols led also to the corresponding saturated ketones as main products. The procedure was less selective for primary
Journal of Molecular Catalysis A: Chemical, 2008
Various conditions have been tested to obtain efficiently 2-methyl-1-indanone via the Pd-catalyze... more Various conditions have been tested to obtain efficiently 2-methyl-1-indanone via the Pd-catalyzed 5-endo-trig cyclization of 1-(o-bromophenyl)-2-methylprop-2-en-1-ol. High yield (97%) was obtained at 120 • C in DMF with Pd(OAc) 2 /cinchonine as the catalytic system and NaHCO 3 as the base. Use of this procedure for the synthesis of other substituted indanones led to lower yields but replacing thermal heating by microwave heating improved greatly the results.
Green Chemistry, 2007
... Process Res. Dev., 2000, 4, 270 ; N. Narender, KVV Krishna Mohan, R. Vinod Reddy, P. Srinivas... more ... Process Res. Dev., 2000, 4, 270 ; N. Narender, KVV Krishna Mohan, R. Vinod Reddy, P. Srinivasu, SJ Kulkrani and KV Ragavan, J. Mol. Catal. ... 8, KVV Krishna Mohan, N. Narender, P. Srinivasu, SJ Kulkarni and KV Rhagavan, Synth. Commun., 2004, 34, 2143 Article . ...
Chemical Communications, 2006
A short text about a way changing process can be seen. In Brazilian Portuguese.
Journal of Molecular Catalysis B Enzymatic, 2009
The biotransformation of compounds containing silicon has recently been a subject of much interes... more The biotransformation of compounds containing silicon has recently been a subject of much interest. In this study, a variety of commercially available serine hydrolases were tested for their ability to catalyse the hydrolysis of the silicon-ether bond in a variety of silyl ethers. The hydrolysis of trimethylethoxysilane in buffer was not found to be accelerated by the presence of trypsin, chymotrypsin, or a variety of other lipase and protease enzymes. Cleavage of a range of alternative silyl ether substrates, including a trimethylsilyl (TMS) ether, by these hydrolases was also not observed, but, interestingly, only two of the enzymes tested were able to cleave a t-butyl ␣,␣,␣-carboxylate that was approximately isosteric with the TMS-protected substrate. This suggests that the cleavage of Si-O bonds by serine hydrolases, such as the cathepsin homolog silicatein-␣, may be in part limited by steric effects, as the reactive centre in the substrate is always, by analogy to C-centred substrates, tertiary, and thus inherently sterically demanding regardless of the putative catalytic competence of the enzymes.
ChemInform, 2001
reactions of organo-metal compounds reactions of organo-metal compounds O 0350 17 -077
Tetrahedron Letters, 2002
Heating secondary benzylic alcohols in molten tetra-n-butyl ammonium bromide with catalytic amoun... more Heating secondary benzylic alcohols in molten tetra-n-butyl ammonium bromide with catalytic amounts of palladium chloride under a gentle flow of argon produced corresponding ketones in good yields. Neither cooxidant nor additive were required, with the added advantage of catalyst and ammonium salt recycling. The dehydrogenation of primary benzylic alcohols was less selective. Such a reaction was ineffective from allylic and saturated alcohols.
Phosphorus, Sulfur, and Silicon and the Related Elements, 2006
ABSTRACT
New Journal of Chemistry, 2004
Carbon-carbon double bonds have been selectively hydrogenated at room temperature in the presence... more Carbon-carbon double bonds have been selectively hydrogenated at room temperature in the presence of benzyloxy groups using an atmospheric pressure of hydrogen, toluene or [bmim]PF 6 as the solvent and palladium nanoparticles stabilized with tetrabutylammonium bromide. The system [bmim]PF 6 /palladium nanoparticles can be recycled without noticeable decrease of activity.
Journal of Organometallic Chemistry, 2001
The Heck coupling of ArX (X =I, Br) with allylic alcohols, carried out at 80 -120°C in molten n-B... more The Heck coupling of ArX (X =I, Br) with allylic alcohols, carried out at 80 -120°C in molten n-Bu 4 NBr using NaHCO 3 as base and PdCl 2 as catalyst without extra ligands, leads to the corresponding b-arylated carbonyl compounds. After extraction of the organic materials with diethyl ether, the ionic layer can be reused directly.
Journal of Organometallic Chemistry, 2003
A novel reaction sequence leading to the synthesis of substituted biphenyls containing a carbonyl... more A novel reaction sequence leading to the synthesis of substituted biphenyls containing a carbonyl group in an aliphatic chain has been achieved in one-pot reaction starting from iodoarenes and allylic alcohols under the catalytic action of palladium and norbornene. The latter is temporarily incorporated into a palladacycle, which directs the reaction towards the selective formation of an aryl Ã/aryl bond. Norbornene spontaneously deinserts to allow the biphenylylpalladium bond thus formed to react in its turn with the allylic alcohol. #
Journal of Molecular Catalysis B: Enzymatic, 2009
The biotransformation of compounds containing silicon has recently been a subject of much interes... more The biotransformation of compounds containing silicon has recently been a subject of much interest. In this study, a variety of commercially available serine hydrolases were tested for their ability to catalyse the hydrolysis of the silicon-ether bond in a variety of silyl ethers. The hydrolysis of trimethylethoxysilane in buffer was not found to be accelerated by the presence of trypsin, chymotrypsin, or a variety of other lipase and protease enzymes. Cleavage of a range of alternative silyl ether substrates, including a trimethylsilyl (TMS) ether, by these hydrolases was also not observed, but, interestingly, only two of the enzymes tested were able to cleave a t-butyl ␣,␣,␣-carboxylate that was approximately isosteric with the TMS-protected substrate. This suggests that the cleavage of Si-O bonds by serine hydrolases, such as the cathepsin homolog silicatein-␣, may be in part limited by steric effects, as the reactive centre in the substrate is always, by analogy to C-centred substrates, tertiary, and thus inherently sterically demanding regardless of the putative catalytic competence of the enzymes.
Journal of Molecular Catalysis A: Chemical, 2004
Saturated ketones have been produced by heating secondary allylic alcohols and catalytic amounts ... more Saturated ketones have been produced by heating secondary allylic alcohols and catalytic amounts of PdCl2 or Pd(OAc)2 in molten n-Bu4NBr. After extraction of the organic material with diethyl ether, the ionic layer and the catalyst can be reused directly. Linear secondary homoallylic alcohols led also to the corresponding saturated ketones as main products. The procedure was less selective for primary
Journal of Molecular Catalysis A: Chemical, 2008
Various conditions have been tested to obtain efficiently 2-methyl-1-indanone via the Pd-catalyze... more Various conditions have been tested to obtain efficiently 2-methyl-1-indanone via the Pd-catalyzed 5-endo-trig cyclization of 1-(o-bromophenyl)-2-methylprop-2-en-1-ol. High yield (97%) was obtained at 120 • C in DMF with Pd(OAc) 2 /cinchonine as the catalytic system and NaHCO 3 as the base. Use of this procedure for the synthesis of other substituted indanones led to lower yields but replacing thermal heating by microwave heating improved greatly the results.
Green Chemistry, 2007
... Process Res. Dev., 2000, 4, 270 ; N. Narender, KVV Krishna Mohan, R. Vinod Reddy, P. Srinivas... more ... Process Res. Dev., 2000, 4, 270 ; N. Narender, KVV Krishna Mohan, R. Vinod Reddy, P. Srinivasu, SJ Kulkrani and KV Ragavan, J. Mol. Catal. ... 8, KVV Krishna Mohan, N. Narender, P. Srinivasu, SJ Kulkarni and KV Rhagavan, Synth. Commun., 2004, 34, 2143 Article . ...
Chemical Communications, 2006