Andrzej Wolan - Academia.edu (original) (raw)
Papers by Andrzej Wolan
Tetrahedron, Sep 1, 2009
A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with di... more A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with dialkyl carbonates under Kulinkovich-type reaction conditions is presented. The influence of the structures of the coupling partners on the yields and regioselectivities of this transformation is described.
Tetrahedron Letters, 2015
Food and Bioprocess Technology, 2015
Dyes and Pigments, 2015
ABSTRACT The synthesis of 4,4′-dibenzodifuran-2,2′-bipyridine derivatives as ligands of organic r... more ABSTRACT The synthesis of 4,4′-dibenzodifuran-2,2′-bipyridine derivatives as ligands of organic ruthenium dyes for DSSC applications is described. Two new heteroleptic ruthenium complexes have been prepared and compared with commercially available N719 and Z907 dyes, using dip dyeing and flow dyeing methods in large area testing cells prepared for industrial purposes. The newly synthesized dyes revealed higher solar-to-electric energy conversion efficiency (η), measured at the AM1.5G conditions, up to 21% compared to N719 and up to 46% compared to Z907, and external quantum efficiency of 53%. These results can be explained by enhanced light-harvesting of the benzodifuran moiety of the dyes that is related to photocurrent.
ChemInform, 2003
Enolization-aldolization of conjugated ketones, enantioselective synthesis of benzofuryl β-amino ... more Enolization-aldolization of conjugated ketones, enantioselective synthesis of benzofuryl β-amino alcohols, and synthesis of p-dihydroxyborylphenylalanine (BPA) and its analogs are described. Aldolization of benzaldehyde with lithium dienolates derived from unhindered conjugated cyclohexenones favored anti selectivity, whereas syn selectivity was favored for hindered cyclohexenones. Anti-aldols were preferentially formed from dienolborinates derived from conjugated cyklohexenones, however, competing aldolization at the 2-position was observed for hindered ketones. Benzofuryl β-amino alcohols were prepared using as a key step the enantioselective reduction of the corresponding α-bromoacetylbenzofurans with (-)-B-chlorodiisopinocampheylborane. Ionic liquids were used as solvents for the synthesis of BPA by the Suzuki cross-coupling reaction. The reaction time is short, and a solution of the catalyst in the ionic liquid can be recycled.
ChemInform, 2011
ABSTRACT The title reaction proceeds under Barbier conditions to afford the corresponding homoall... more ABSTRACT The title reaction proceeds under Barbier conditions to afford the corresponding homoallylic hydroxylamine esters.
ChemInform, 2010
A Convenient Titanium-Mediated Intermolecular Alkyne-Carbonate Coupling Reaction. -Kulinkovich-ty... more A Convenient Titanium-Mediated Intermolecular Alkyne-Carbonate Coupling Reaction. -Kulinkovich-type reaction of internal alkynes with carbonates provides access towards ene-carboxylates, e.g. (III)/(IV) or (XI)/(XII), in excellent E/Z-selectivity. The regioselectivity, however, is strongly influenced by the nature of substituents at the alkyne. Main side products are the reduction products (V). The second position of the alkene can be filled by reaction with an electrophile like iodine or benzaldehyde [cf. (XVII), (XIX)]. -(WOLAN, A.; CADORET, F.; SIX*, Y.; Tetrahedron 65 (2009) 36, 7429-7439; Inst. Chim. Subst. Nat., CNRS, F-91198 Gif-sur-Yvette, Fr.; Eng.) -Mischke 02-053
Comprehensive Organic Synthesis II, 2014
![Research paper thumbnail of Tactics for the asymmetric preparation of 2-azabicyclo[3.1.0]hexane and 2-azabicyclo[4.1.0]heptane scaffolds](https://attachments.academia-assets.com/52076180/thumbnails/1.jpg)
](Tetrahedron Letters, 2011
In this contribution, two methods are presented for the removal of benzyl-type protecting groups ... more In this contribution, two methods are presented for the removal of benzyl-type protecting groups attached to the nitrogen atom of 2-azabicyclo[3.1.0]hexane and 2-azabicyclo[4.1.0]heptane systems. The first, based on the Polonovski reaction, is suitable for [3.1.0] systems. The second relies on an elimination process, starting from derivatives of O-methyl phenylglycinol, and is more general in terms of the substrates tolerated. Secondary bicyclic cyclopropylamines, including enantiomerically pure molecules, can thus be accessed. These compounds are then ready for further functionalisation.
Tetrahedron Letters, 2011
A facile zinc-mediated Barbier-type allylation of aromatic aldoxime esters, producing the corresp... more A facile zinc-mediated Barbier-type allylation of aromatic aldoxime esters, producing the corresponding protected homoallylic hydroxylamines, which are readily converted into homoallylic hydroxamic acids, is described.
Tetrahedron, 2009
A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with di... more A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with dialkyl carbonates under Kulinkovich-type reaction conditions is presented. The influence of the structures of the coupling partners on the yields and regioselectivities of this transformation is described.
Pure and Applied Chemistry, 2000
Organic & Biomolecular Chemistry, 2003
The palladium catalysed cross-coupling reaction of aryl iodides and bromides with pinacolborane i... more The palladium catalysed cross-coupling reaction of aryl iodides and bromides with pinacolborane in 1,3-dialkylimidazolium tetrafluoroborates and hexafluorophosphates producing arylboronates is described.
Journal of Organometallic Chemistry, 2002
v-(4-Bromophenyl)alkanoic acids 2c Á/e were obtained from 1-bromo-4-alkenylbenzenes 5c Á/e by hyd... more v-(4-Bromophenyl)alkanoic acids 2c Á/e were obtained from 1-bromo-4-alkenylbenzenes 5c Á/e by hydroboration Á/thermal isomerization Á/oxidation. Their esters 11c Á/e were transformed in good yields into the corresponding boronates 12c Á/e by the cross-coupling reaction with 4,4,5,5,4?,4?,5?,5?-octamethyl[2,2?]bi [[1,3,2]dioxaborolanyl] (10) in an ionic liquid, [bmim] [BF 4 ]. The use of pinacolborane for the coupling reaction in the ionic liquid gave debromination products, and low yields of 12c Á/e. Ethyl 3-(4bromophenyl)propanoate (7c) was transformed into ethyl 3-(4-[1,3,2]dioxaborolanyl)propanoate (9c) by the cross-coupling with [2,2?]bi [[1,3,2]dioxaborinanyl]. #
Biocatalysis and Biotransformation, 2012
ABSTRACT The influence of solvent and acyl group donor on selectivity of the transesterification ... more ABSTRACT The influence of solvent and acyl group donor on selectivity of the transesterification reaction of 1-[1′,3′-dihydroxy-2′-propoxymethyl]-5-methyluracil, a structural analogue of ganciclovir was examined. Lipase (EC 3.1.1.3) B from Candida antarctica (CALB) enabled desymmetrization of prochiral hydroxyl groups when 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) was used as a reaction medium. It was observed that CALB was up to 2.7–4 times more enantioselective in the ionic liquid [Bmim][PF6] than in conventional organic solvents.
Tetrahedron, Sep 1, 2009
A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with di... more A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with dialkyl carbonates under Kulinkovich-type reaction conditions is presented. The influence of the structures of the coupling partners on the yields and regioselectivities of this transformation is described.
Tetrahedron Letters, 2015
Food and Bioprocess Technology, 2015
Dyes and Pigments, 2015
ABSTRACT The synthesis of 4,4′-dibenzodifuran-2,2′-bipyridine derivatives as ligands of organic r... more ABSTRACT The synthesis of 4,4′-dibenzodifuran-2,2′-bipyridine derivatives as ligands of organic ruthenium dyes for DSSC applications is described. Two new heteroleptic ruthenium complexes have been prepared and compared with commercially available N719 and Z907 dyes, using dip dyeing and flow dyeing methods in large area testing cells prepared for industrial purposes. The newly synthesized dyes revealed higher solar-to-electric energy conversion efficiency (η), measured at the AM1.5G conditions, up to 21% compared to N719 and up to 46% compared to Z907, and external quantum efficiency of 53%. These results can be explained by enhanced light-harvesting of the benzodifuran moiety of the dyes that is related to photocurrent.
ChemInform, 2003
Enolization-aldolization of conjugated ketones, enantioselective synthesis of benzofuryl β-amino ... more Enolization-aldolization of conjugated ketones, enantioselective synthesis of benzofuryl β-amino alcohols, and synthesis of p-dihydroxyborylphenylalanine (BPA) and its analogs are described. Aldolization of benzaldehyde with lithium dienolates derived from unhindered conjugated cyclohexenones favored anti selectivity, whereas syn selectivity was favored for hindered cyclohexenones. Anti-aldols were preferentially formed from dienolborinates derived from conjugated cyklohexenones, however, competing aldolization at the 2-position was observed for hindered ketones. Benzofuryl β-amino alcohols were prepared using as a key step the enantioselective reduction of the corresponding α-bromoacetylbenzofurans with (-)-B-chlorodiisopinocampheylborane. Ionic liquids were used as solvents for the synthesis of BPA by the Suzuki cross-coupling reaction. The reaction time is short, and a solution of the catalyst in the ionic liquid can be recycled.
ChemInform, 2011
ABSTRACT The title reaction proceeds under Barbier conditions to afford the corresponding homoall... more ABSTRACT The title reaction proceeds under Barbier conditions to afford the corresponding homoallylic hydroxylamine esters.
ChemInform, 2010
A Convenient Titanium-Mediated Intermolecular Alkyne-Carbonate Coupling Reaction. -Kulinkovich-ty... more A Convenient Titanium-Mediated Intermolecular Alkyne-Carbonate Coupling Reaction. -Kulinkovich-type reaction of internal alkynes with carbonates provides access towards ene-carboxylates, e.g. (III)/(IV) or (XI)/(XII), in excellent E/Z-selectivity. The regioselectivity, however, is strongly influenced by the nature of substituents at the alkyne. Main side products are the reduction products (V). The second position of the alkene can be filled by reaction with an electrophile like iodine or benzaldehyde [cf. (XVII), (XIX)]. -(WOLAN, A.; CADORET, F.; SIX*, Y.; Tetrahedron 65 (2009) 36, 7429-7439; Inst. Chim. Subst. Nat., CNRS, F-91198 Gif-sur-Yvette, Fr.; Eng.) -Mischke 02-053
Comprehensive Organic Synthesis II, 2014
Tetrahedron Letters, 2011
In this contribution, two methods are presented for the removal of benzyl-type protecting groups ... more In this contribution, two methods are presented for the removal of benzyl-type protecting groups attached to the nitrogen atom of 2-azabicyclo[3.1.0]hexane and 2-azabicyclo[4.1.0]heptane systems. The first, based on the Polonovski reaction, is suitable for [3.1.0] systems. The second relies on an elimination process, starting from derivatives of O-methyl phenylglycinol, and is more general in terms of the substrates tolerated. Secondary bicyclic cyclopropylamines, including enantiomerically pure molecules, can thus be accessed. These compounds are then ready for further functionalisation.
Tetrahedron Letters, 2011
A facile zinc-mediated Barbier-type allylation of aromatic aldoxime esters, producing the corresp... more A facile zinc-mediated Barbier-type allylation of aromatic aldoxime esters, producing the corresponding protected homoallylic hydroxylamines, which are readily converted into homoallylic hydroxamic acids, is described.
Tetrahedron, 2009
A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with di... more A direct diastereoselective titanium-mediated intermolecular coupling of internal alkynes with dialkyl carbonates under Kulinkovich-type reaction conditions is presented. The influence of the structures of the coupling partners on the yields and regioselectivities of this transformation is described.
Pure and Applied Chemistry, 2000
Organic & Biomolecular Chemistry, 2003
The palladium catalysed cross-coupling reaction of aryl iodides and bromides with pinacolborane i... more The palladium catalysed cross-coupling reaction of aryl iodides and bromides with pinacolborane in 1,3-dialkylimidazolium tetrafluoroborates and hexafluorophosphates producing arylboronates is described.
Journal of Organometallic Chemistry, 2002
v-(4-Bromophenyl)alkanoic acids 2c Á/e were obtained from 1-bromo-4-alkenylbenzenes 5c Á/e by hyd... more v-(4-Bromophenyl)alkanoic acids 2c Á/e were obtained from 1-bromo-4-alkenylbenzenes 5c Á/e by hydroboration Á/thermal isomerization Á/oxidation. Their esters 11c Á/e were transformed in good yields into the corresponding boronates 12c Á/e by the cross-coupling reaction with 4,4,5,5,4?,4?,5?,5?-octamethyl[2,2?]bi [[1,3,2]dioxaborolanyl] (10) in an ionic liquid, [bmim] [BF 4 ]. The use of pinacolborane for the coupling reaction in the ionic liquid gave debromination products, and low yields of 12c Á/e. Ethyl 3-(4bromophenyl)propanoate (7c) was transformed into ethyl 3-(4-[1,3,2]dioxaborolanyl)propanoate (9c) by the cross-coupling with [2,2?]bi [[1,3,2]dioxaborinanyl]. #
Biocatalysis and Biotransformation, 2012
ABSTRACT The influence of solvent and acyl group donor on selectivity of the transesterification ... more ABSTRACT The influence of solvent and acyl group donor on selectivity of the transesterification reaction of 1-[1′,3′-dihydroxy-2′-propoxymethyl]-5-methyluracil, a structural analogue of ganciclovir was examined. Lipase (EC 3.1.1.3) B from Candida antarctica (CALB) enabled desymmetrization of prochiral hydroxyl groups when 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) was used as a reaction medium. It was observed that CALB was up to 2.7–4 times more enantioselective in the ionic liquid [Bmim][PF6] than in conventional organic solvents.