Vito Capriati | Università degli Studi di Bari (original) (raw)
Papers by Vito Capriati
The Journal of Organic Chemistry, 2004
The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well a... more The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well as the trapping reaction with electrophiles. The reduction of the cis-alpha-benzoylpropylene oxide to give prevalently the anti-epoxy alcohol has been investigated as well.
Tetrahedron, 2010
The influence of the sulfinyl group as a chiral auxiliary in the stereoselective addition of oxir... more The influence of the sulfinyl group as a chiral auxiliary in the stereoselective addition of oxiranyllithiums to (S)-2-p-tolylsulfinylbenzaldehyde has been studied. All reactions evolve with retention of configuration at the starting lithiated carbon. Completely stereoselective additions have been observed when configurations at sulfur and the lithiated carbon are different (matched pair), whereas variable dr's values (ranging between 52:48 and >99:<1%) when they are identical (mismatched pair).
The Journal of Organic Chemistry, 2004
The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well a... more The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well as the trapping reaction with electrophiles. The reduction of the cis-alpha-benzoylpropylene oxide to give prevalently the anti-epoxy alcohol has been investigated as well.
Organic Letters, 2005
[reaction: see text] A stereoselective/stereospecific synthesis of polysubstituted tetrahydronaph... more [reaction: see text] A stereoselective/stereospecific synthesis of polysubstituted tetrahydronaphthols based on the Michael addition of ortho-lithiated stilbene oxides to alpha,beta-unsaturated Fischer carbene complexes followed by an unusual cyclization of the corresponding intermediate in a 6-endo-tet mode is described.
Angewandte Chemie International Edition, 2012
More than seventy years ago, Gilman and Wittig independently observed that the lithiation of an a... more More than seventy years ago, Gilman and Wittig independently observed that the lithiation of an aromatic ring could be achieved ortho to a substituent, and hence opened up new horizons for obtaining differently functionalized organolithium derivatives through what is today known as the directed ortho metalation (DoM) reaction. Since then, and particularly thanks to seminal contributions from the groups of Hauser, Meyers, Gschwend, Beak, Snieckus, and others, DoM methodology, which strikingly complements traditional electrophilic aromatic substitution, has received an extraordinary level of attention in the field of organometallic chemistry. The reaction is proposed to proceed by the involvement of a direct metalation group (DMG) whose ability to effect the ortho metalation process has generally been interpreted in terms of an interplay of inductive and complexation effects. The mechanistic rationalization for the DoM reaction, however, still remains elusive and controversial. Despite the broad range of hetero-and carbon-linked substituents available to synthetic chemists for performing hydrogen/metal permutation processes, saturated ring heterocycles have surprisingly received much less attention as potential DMGs. The oxetane ring motif is an important structural component of several naturally occurring compounds, and oxetane derivatives have received increasing exposure over the years as attractive and versatile modules for both drug discovery and organic synthesis. Herein, we report the first successful use of oxetane as an effective DMG in the regioselective preparation of functionalized 2-aryloxetane scaffolds and explore the scope of such a methodology. On the basis of intra-and intermolecular competition experiments and kinetic evidence, we rank the lithiation-promoting power of oxetane as being equal to that of an aminomethyl group, and support a complex-induced proximity effect (CIPE) as the main mechanism responsible for modulating the ortho C À H acidity.
Chemical Communications, 2011
A valuable and direct method to access 2-substituted-2-phenyloxetanes by electrophilic quenching ... more A valuable and direct method to access 2-substituted-2-phenyloxetanes by electrophilic quenching of the corresponding 2-lithiated derivative has, for the first time, been described. 2-Lithiated-2phenyloxetane was found to be configurationally unstable. Evidence is presented to show that electron-transfer processes are also operative in the coupling reactions with electrophiles.
Chemistry - A European Journal, 2011
Chemistry - A European Journal, 2010
Chemistry - A European Journal, 2010
Chemistry - A European Journal, 2009
and Cartesian coordinates (B3LYP/6-31 + G(d)) of neutral and lithiated styrene oxide (S3-S15); na... more and Cartesian coordinates (B3LYP/6-31 + G(d)) of neutral and lithiated styrene oxide (S3-S15); natural charge distribution analysis in neutral styrene oxide (S16); natural charge distribution analysis in free (2 a) and solvated lithium styrene oxide (S17); comparison of selected geometrical parameters in free (2 a, 4 a and 4 c) and solvated lithium salt (S18); natural charge distribution analysis in free and solvated dimer (4 c) of lithium styrene oxide (S19); comparison of the theoretical and experimental 13 C NMR shieldings for neutral styrene oxide 1 (S20); theoretical 13 C NMR shieldings in free dimers (4) and solvated lithium salt (S20); natural bond orbital energies of s OÀCa and s* OÀCa orbitals in neutral and lithiated styrene oxide in different aggregates and solvated forms (S20); optimised structures for neutral 1 and side views of 4 a-4 d (S21-S23); 1D and 2D NMR spectra (S23-S27); schematic drawings of additional aggregates (S27).
Tetrahedron, 2009
The synthesis of terminal oxazolinyloxiranes, even in enantioenriched form, has been performed by... more The synthesis of terminal oxazolinyloxiranes, even in enantioenriched form, has been performed by Darzens-type reaction of lithiated chloroalkyloxazolines with benzotriazolylmethanol (BtCH2OH) or by chloromethylation of 2-acyl-2-oxazolines. The ...
Organic Letters, 2008
A short and efficient synthesis of tetrahydroindenofuranones based on the Michael addition of ort... more A short and efficient synthesis of tetrahydroindenofuranones based on the Michael addition of ortho-lithiated aryloxiranes to alkylidene malonates followed by the nucleophilic oxirane ring-opening and subsequent lactonization is described. The methodology has been applied to the synthesis of a structural analogue of epipodophyllotoxins.
The Journal of Organic Chemistry, 2008
The R-lithiation-trapping sequence of trans-N-alkyl-2,3-diphenylaziridines (s-BuLi or s-BuLi/TMED... more The R-lithiation-trapping sequence of trans-N-alkyl-2,3-diphenylaziridines (s-BuLi or s-BuLi/TMEDA), taking place with a stereochemistry which dramatically depends on the solvent coordinating ability (inversion of configuration in THF and retention in toluene), has been carefully investigated. 1 H, 13 C, and 7 Li multinuclear NMR investigations at low temperature suggest that two differently configured lithiated aziridines (monomeric cis-1-Li in THF and dimeric trans-1-Li in toluene) are involved.
Chemical Reviews, 2008
Saverio Florio received his Laurea in Chemistry at the University of Bari (Italy) and started h... more Saverio Florio received his Laurea in Chemistry at the University of Bari (Italy) and started his academic career there, first as Assistant Professor (1969) and then as Associate Professor of Organic Chemistry (1982). In 1986, he was appointed Full Professor of ...
Tetrahedron Letters, 2007
The reaction of α-lithiated-2-alkyl-2-oxazolines 1-Li with aliphatic, aromatic and heteroaromatic... more The reaction of α-lithiated-2-alkyl-2-oxazolines 1-Li with aliphatic, aromatic and heteroaromatic N-cumyl nitrones results in the stereoselective formation of N-cumyl-1, 6-dioxa-2, 9-diazaspiro [4, 4] nonanes 3 which equilibrate with the hydroxylamino ...
Organic Letters, 2007
[structure: see text]. The lithiation reaction of cis- and trans-N-alkyl-2,3-diphenylaziridines h... more [structure: see text]. The lithiation reaction of cis- and trans-N-alkyl-2,3-diphenylaziridines has been investigated. While cis-diphenylaziridines do not undergo any lithiation upon treatment with organolithiums, the lithiation reaction of the trans counterparts is completely alpha-regioselective and the stereochemical course of the lithiation-trapping sequence is solvent dependent: inversion of configuration in coordinating solvents (THF or toluene/crown ether) and retention in hexane, ether, or toluene. The preparation of stereodefined functionalized N-alkyl-2,3-diphenylaziridines is described.
The Journal of Organic Chemistry, 2007
A general method for the synthesis of 2,3-dihydro-10bH-oxazolo[2,3-a]isoquinolines from the react... more A general method for the synthesis of 2,3-dihydro-10bH-oxazolo[2,3-a]isoquinolines from the reaction of (R*,R*)-configured ortho-bromophenyloxazolinyloxiranes and organolithiums is described.
Zeitschrift für Kristallographie - New Crystal Structures, 2000
C 19H23NO2, Pbc21 (no. 29), a = 9.481(1) Å, b = 12.073(1) Å, c = 30.079(5) Å, V = 3443.0 Å 3 , Z ... more C 19H23NO2, Pbc21 (no. 29), a = 9.481(1) Å, b = 12.073(1) Å, c = 30.079(5) Å, V = 3443.0 Å 3 , Z = 8, R gt (F) = 0.077, wR ref (F 2 ) = 0.217, T = 293 K.
The Journal of Organic Chemistry, 2004
The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well a... more The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well as the trapping reaction with electrophiles. The reduction of the cis-alpha-benzoylpropylene oxide to give prevalently the anti-epoxy alcohol has been investigated as well.
Tetrahedron, 2010
The influence of the sulfinyl group as a chiral auxiliary in the stereoselective addition of oxir... more The influence of the sulfinyl group as a chiral auxiliary in the stereoselective addition of oxiranyllithiums to (S)-2-p-tolylsulfinylbenzaldehyde has been studied. All reactions evolve with retention of configuration at the starting lithiated carbon. Completely stereoselective additions have been observed when configurations at sulfur and the lithiated carbon are different (matched pair), whereas variable dr's values (ranging between 52:48 and >99:<1%) when they are identical (mismatched pair).
The Journal of Organic Chemistry, 2004
The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well a... more The stereospecific lithiation of diastereomeric phenylpropylene oxides has been studied as well as the trapping reaction with electrophiles. The reduction of the cis-alpha-benzoylpropylene oxide to give prevalently the anti-epoxy alcohol has been investigated as well.
Organic Letters, 2005
[reaction: see text] A stereoselective/stereospecific synthesis of polysubstituted tetrahydronaph... more [reaction: see text] A stereoselective/stereospecific synthesis of polysubstituted tetrahydronaphthols based on the Michael addition of ortho-lithiated stilbene oxides to alpha,beta-unsaturated Fischer carbene complexes followed by an unusual cyclization of the corresponding intermediate in a 6-endo-tet mode is described.
Angewandte Chemie International Edition, 2012
More than seventy years ago, Gilman and Wittig independently observed that the lithiation of an a... more More than seventy years ago, Gilman and Wittig independently observed that the lithiation of an aromatic ring could be achieved ortho to a substituent, and hence opened up new horizons for obtaining differently functionalized organolithium derivatives through what is today known as the directed ortho metalation (DoM) reaction. Since then, and particularly thanks to seminal contributions from the groups of Hauser, Meyers, Gschwend, Beak, Snieckus, and others, DoM methodology, which strikingly complements traditional electrophilic aromatic substitution, has received an extraordinary level of attention in the field of organometallic chemistry. The reaction is proposed to proceed by the involvement of a direct metalation group (DMG) whose ability to effect the ortho metalation process has generally been interpreted in terms of an interplay of inductive and complexation effects. The mechanistic rationalization for the DoM reaction, however, still remains elusive and controversial. Despite the broad range of hetero-and carbon-linked substituents available to synthetic chemists for performing hydrogen/metal permutation processes, saturated ring heterocycles have surprisingly received much less attention as potential DMGs. The oxetane ring motif is an important structural component of several naturally occurring compounds, and oxetane derivatives have received increasing exposure over the years as attractive and versatile modules for both drug discovery and organic synthesis. Herein, we report the first successful use of oxetane as an effective DMG in the regioselective preparation of functionalized 2-aryloxetane scaffolds and explore the scope of such a methodology. On the basis of intra-and intermolecular competition experiments and kinetic evidence, we rank the lithiation-promoting power of oxetane as being equal to that of an aminomethyl group, and support a complex-induced proximity effect (CIPE) as the main mechanism responsible for modulating the ortho C À H acidity.
Chemical Communications, 2011
A valuable and direct method to access 2-substituted-2-phenyloxetanes by electrophilic quenching ... more A valuable and direct method to access 2-substituted-2-phenyloxetanes by electrophilic quenching of the corresponding 2-lithiated derivative has, for the first time, been described. 2-Lithiated-2phenyloxetane was found to be configurationally unstable. Evidence is presented to show that electron-transfer processes are also operative in the coupling reactions with electrophiles.
Chemistry - A European Journal, 2011
Chemistry - A European Journal, 2010
Chemistry - A European Journal, 2010
Chemistry - A European Journal, 2009
and Cartesian coordinates (B3LYP/6-31 + G(d)) of neutral and lithiated styrene oxide (S3-S15); na... more and Cartesian coordinates (B3LYP/6-31 + G(d)) of neutral and lithiated styrene oxide (S3-S15); natural charge distribution analysis in neutral styrene oxide (S16); natural charge distribution analysis in free (2 a) and solvated lithium styrene oxide (S17); comparison of selected geometrical parameters in free (2 a, 4 a and 4 c) and solvated lithium salt (S18); natural charge distribution analysis in free and solvated dimer (4 c) of lithium styrene oxide (S19); comparison of the theoretical and experimental 13 C NMR shieldings for neutral styrene oxide 1 (S20); theoretical 13 C NMR shieldings in free dimers (4) and solvated lithium salt (S20); natural bond orbital energies of s OÀCa and s* OÀCa orbitals in neutral and lithiated styrene oxide in different aggregates and solvated forms (S20); optimised structures for neutral 1 and side views of 4 a-4 d (S21-S23); 1D and 2D NMR spectra (S23-S27); schematic drawings of additional aggregates (S27).
Tetrahedron, 2009
The synthesis of terminal oxazolinyloxiranes, even in enantioenriched form, has been performed by... more The synthesis of terminal oxazolinyloxiranes, even in enantioenriched form, has been performed by Darzens-type reaction of lithiated chloroalkyloxazolines with benzotriazolylmethanol (BtCH2OH) or by chloromethylation of 2-acyl-2-oxazolines. The ...
Organic Letters, 2008
A short and efficient synthesis of tetrahydroindenofuranones based on the Michael addition of ort... more A short and efficient synthesis of tetrahydroindenofuranones based on the Michael addition of ortho-lithiated aryloxiranes to alkylidene malonates followed by the nucleophilic oxirane ring-opening and subsequent lactonization is described. The methodology has been applied to the synthesis of a structural analogue of epipodophyllotoxins.
The Journal of Organic Chemistry, 2008
The R-lithiation-trapping sequence of trans-N-alkyl-2,3-diphenylaziridines (s-BuLi or s-BuLi/TMED... more The R-lithiation-trapping sequence of trans-N-alkyl-2,3-diphenylaziridines (s-BuLi or s-BuLi/TMEDA), taking place with a stereochemistry which dramatically depends on the solvent coordinating ability (inversion of configuration in THF and retention in toluene), has been carefully investigated. 1 H, 13 C, and 7 Li multinuclear NMR investigations at low temperature suggest that two differently configured lithiated aziridines (monomeric cis-1-Li in THF and dimeric trans-1-Li in toluene) are involved.
Chemical Reviews, 2008
Saverio Florio received his Laurea in Chemistry at the University of Bari (Italy) and started h... more Saverio Florio received his Laurea in Chemistry at the University of Bari (Italy) and started his academic career there, first as Assistant Professor (1969) and then as Associate Professor of Organic Chemistry (1982). In 1986, he was appointed Full Professor of ...
Tetrahedron Letters, 2007
The reaction of α-lithiated-2-alkyl-2-oxazolines 1-Li with aliphatic, aromatic and heteroaromatic... more The reaction of α-lithiated-2-alkyl-2-oxazolines 1-Li with aliphatic, aromatic and heteroaromatic N-cumyl nitrones results in the stereoselective formation of N-cumyl-1, 6-dioxa-2, 9-diazaspiro [4, 4] nonanes 3 which equilibrate with the hydroxylamino ...
Organic Letters, 2007
[structure: see text]. The lithiation reaction of cis- and trans-N-alkyl-2,3-diphenylaziridines h... more [structure: see text]. The lithiation reaction of cis- and trans-N-alkyl-2,3-diphenylaziridines has been investigated. While cis-diphenylaziridines do not undergo any lithiation upon treatment with organolithiums, the lithiation reaction of the trans counterparts is completely alpha-regioselective and the stereochemical course of the lithiation-trapping sequence is solvent dependent: inversion of configuration in coordinating solvents (THF or toluene/crown ether) and retention in hexane, ether, or toluene. The preparation of stereodefined functionalized N-alkyl-2,3-diphenylaziridines is described.
The Journal of Organic Chemistry, 2007
A general method for the synthesis of 2,3-dihydro-10bH-oxazolo[2,3-a]isoquinolines from the react... more A general method for the synthesis of 2,3-dihydro-10bH-oxazolo[2,3-a]isoquinolines from the reaction of (R*,R*)-configured ortho-bromophenyloxazolinyloxiranes and organolithiums is described.
Zeitschrift für Kristallographie - New Crystal Structures, 2000
C 19H23NO2, Pbc21 (no. 29), a = 9.481(1) Å, b = 12.073(1) Å, c = 30.079(5) Å, V = 3443.0 Å 3 , Z ... more C 19H23NO2, Pbc21 (no. 29), a = 9.481(1) Å, b = 12.073(1) Å, c = 30.079(5) Å, V = 3443.0 Å 3 , Z = 8, R gt (F) = 0.077, wR ref (F 2 ) = 0.217, T = 293 K.