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Publications (10 of 108) Show all publications
Bellini, R., Magre, M., Biosca, M., Norrby, P.-O., Pamies, O., Dieguez, M. & Moberg, C. (2016). Conformational Preferences of a Tropos Biphenyl Phosphinooxazoline-a Ligand with Wide Substrate Scope. ACS Catalysis, 6(3), 1701-1712
Open this publication in new window or tab >>Conformational Preferences of a Tropos Biphenyl Phosphinooxazoline-a Ligand with Wide Substrate Scope
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2016 (English)In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 6, no 3, p. 1701-1712Article in journal (Refereed) Published
Abstract [en]

Excellent enantioselectivities are observed in palladium-catalyzed allylic substitutions of a wide range of substrate types and nucleophiles using a bidentate ligand composed of oxazoline and chirally flexible biaryl phosphite elements. This unusually wide substrate scope is shown by experimental and theoretical studies of its eta(3)-allyl and eta(2)-olefin complexes not to be a result of configurational interconversion of the biaryl unit, since the ligand in all reactions adopts an S-a,S configuration on coordination to palladium, but rather the ability of the ligand to adapt the size of the substrate-binding pocket to the reacting substrate. This ability also serves as an explanation to its excellent performance in other types of catalytic processes.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016
Keywords
palladium, allylic substitution, tropos P, N-ligands, NMR study, DFT study
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-184535 (URN)10.1021/acscatal.5b02766 (DOI)000371755500038 ()2-s2.0-84960192423 (Scopus ID)
Funder
Swedish Research Council, 621-2012-3391
Note

QC 20160406

Available from: 2016-04-06 Created: 2016-04-01 Last updated: 2017-11-30Bibliographically approved
Laurell Nash, A., Hertzberg, R., Wen, Y.-Q., Dahlgren, B., Brinck, T. & Moberg, C. (2016). Dual Lewis Acid/Lewis Base Catalyzed Acylcyanation of Aldehydes: A Mechanistic Study. Chemistry - A European Journal, 22(11), 3821-3829
Open this publication in new window or tab >>Dual Lewis Acid/Lewis Base Catalyzed Acylcyanation of Aldehydes: A Mechanistic Study
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2016 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 22, no 11, p. 3821-3829Article in journal (Refereed) Published
Abstract [en]

A mechanistic investigation, which included a Hammett correlation analysis, evaluation of the effect of variation of catalyst composition, and low-temperature NMR spectroscopy studies, of the Lewis acid-Lewis base catalyzed addition of acetyl cyanide to prochiral aldehydes provides support for a reaction route that involves Lewis base activation of the acyl cyanide with formation of a potent acylating agent and cyanide ion. The cyanide ion adds to the carbonyl group of the Lewis acid activated aldehyde. O-Acylation by the acylated Lewis base to form the final cyanohydrin ester occurs prior to decomplexation from titanium. For less reactive aldehydes, the addition of cyanide is the rate-determining step, whereas, for more reactive, electron-deficient aldehydes, cyanide addition is rapid and reversible and is followed by rate-limiting acylation. The resting state of the catalyst lies outside the catalytic cycle and is believed to be a monomeric titanium complex with two alcoholate ligands, which only slowly converts into the product.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2016
Keywords
asymmetric catalysis, Lewis acids, Lewis bases, reaction mechanisms, titanium
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-184528 (URN)10.1002/chem.201503782 (DOI)000371741400037 ()2-s2.0-84959536218 (Scopus ID)
Note

QC 20160406

Available from: 2016-04-06 Created: 2016-04-01 Last updated: 2017-11-30Bibliographically approved
Moberg, C. (2016). Recycling in Asymmetric Catalysis. ACCOUNTS OF CHEMICAL RESEARCH, 49(12), 2736-2745
Open this publication in new window or tab >>Recycling in Asymmetric Catalysis
2016 (English)In: ACCOUNTS OF CHEMICAL RESEARCH, ISSN 0001-4842, Vol. 49, no 12, p. 2736-2745Article, review/survey (Refereed) Published
Abstract [en]

CONSPECTUS: Cyclic reaction networks consisting of an enantioselective product forming step and a reverse reaction of the undesired enantiomer back to starting reactant are important for the generation of compounds with high enantiomeric purity. In order to avoid an equilibrium racemic state, a unidirectional cyclic process where product formation and regeneration of starting reactant proceed through different mechanistic pathways is required. Such processes must necessarily include a thermodynamically unfavorable step, since the product of the forward reaction is the reactant of the reverse reaction and vice versa. Thermodynamically uphill processes are ubiquitous to the function of living systems. Such systems gain the required energy by coupling to thermodynamically downhill reactions. In the same way, artificial cyclic reaction networks can be realized in systems open to mass or energy flow, and an out-of equilibrium nonracemic steady state can be maintained as long as the system is supplied with energy. In contrast to a kinetic resolution, a recycling process where the minor enantiomer is converted to starting reactant can result in a quantitative yield, but the enantiomeric purity of the product is limited by the selectivity of the catalysts used for the reactions. On the other hand, in a kinetic resolution, the slowly reacting enantiomer can always be obtained in an enantiomerically pure state, although the yield will suffer. In cyclic reaction systems which use chiral catalysts for both the forward and the reverse processes, a reinforcing effect results, and selectivities higher than those achieved by a single chiral catalyst are observed. A dynamic kinetic resolution can in principle also lead to a quantitative yield, but lacks the reinforcing effect of two chiral catalysts. Most examples of cyclic reaction networks reported in the literature are deracemizations of racemic mixtures, which proceed via oxidation of one enantiomer followed by reduction to the opposite enantiomer. We have developed cyclic reaction networks comprising a carbon carbon bond formation. In these processes, the product is generated by the addition of a cyanide reagent to a prochiral aldehyde. This is followed by hydrolysis of the minor enantiomer of the product to generate the starting aldehyde. A unidirectional cycle is maintained by coupling to the exergonic transformation of the high potential cyanide reagent to a low potential compound, either a carboxylate or carbon dioxide. The products, which are obtained with high enantiomeric purity, serve as valuable starting materials for a variety of biologically and pharmaceutically active compounds.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-200218 (URN)10.1021/acs.accounts.6b00396 (DOI)000390619500008 ()2-s2.0-85007040157 (Scopus ID)
Note

QC 20170214

Available from: 2017-02-14 Created: 2017-02-14 Last updated: 2017-03-07Bibliographically approved
Li, E., Zhou, H., Östlund, V., Hertzberg, R. & Moberg, C. (2016). Regio- and stereoselective synthesis of conjugated trienes from silaborated 1,3-enynes. Paper presented at 6th EuCheMS Conference on Nitrogen Ligands, SEP, 2015, Beaune, FRANCE. New Journal of Chemistry, 40(7), 6340-6346
Open this publication in new window or tab >>Regio- and stereoselective synthesis of conjugated trienes from silaborated 1,3-enynes
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2016 (English)In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 40, no 7, p. 6340-6346Article in journal (Refereed) Published
Abstract [en]

Products obtained from palladium-catalyzed regioselective cis-addition of (chlorodimethylsilyl)pinacolborane to the alkyne bond of 1,4-disubstituted 1,3-enynes were subjected to Suzuki-Miyaura coupling with alkenyl iodides. Hiyama coupling of the resulting silanol-functionalized trienes provided tetrasubstituted conjugated trienes with different substitution patterns, whereas protiodesilylation with fluoride gave trisubstituted trienes. The methodology presented gives access to conjugated trienes with control of regio- and stereochemistry.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016
Keywords
2 propanol, alkyne, boron, iodobenzene, palladium, silanol, silicon, trientine, Article, catalyst, chemical modification, column chromatography, desilylation, hydroboration, hydrosilylation, priority journal, protiodeboronation, protiodesilylation, proton nuclear magnetic resonance, purification, stereochemistry, Suzuki reaction, synthesis
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-195480 (URN)10.1039/c6nj01019a (DOI)000385869600085 ()2-s2.0-84979022019 (Scopus ID)
Conference
6th EuCheMS Conference on Nitrogen Ligands, SEP, 2015, Beaune, FRANCE
Note

QC 20161125

Available from: 2016-11-25 Created: 2016-11-03 Last updated: 2017-11-29Bibliographically approved
Xiao, Y.-C. & Moberg, C. (2016). Silaborative Carbocyclizations of 1,7-Enynes. Diastereoselective Preparation of Chromane Derivatives. Organic Letters, 18(2), 308-311
Open this publication in new window or tab >>Silaborative Carbocyclizations of 1,7-Enynes. Diastereoselective Preparation of Chromane Derivatives
2016 (English)In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 18, no 2, p. 308-311Article in journal (Refereed) Published
Abstract [en]

Palladium(0)-catalyzed carbocyclization of 1,7-enynes mediated by (chlorodimethylsilyl)pinacolborane proceeds with 1,8-addition of the silicon and boron functions to give functionalized cyclohexane derivatives with boron attached to the exocyclic olefin. A variety of chromane dervatives are accessible by this method. In contrast to the analogous reactions with 1,6-enynes, the configuration of the newly formed stereogenic center is controlled by a stereogenic center present in the substrate.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-182157 (URN)10.1021/acs.orglett.5b03479 (DOI)000368563200041 ()26741486 (PubMedID)2-s2.0-84955458738 (Scopus ID)
Note

QC 20160220

Available from: 2016-02-20 Created: 2016-02-16 Last updated: 2017-11-30Bibliographically approved
Hertzberg, R., Santiago, G. M. & Moberg, C. (2015). Synthesis of the beta(3)-Adrenergic Receptor Agonist Solabegron and Analogous N-(2-Ethylamino)-beta-amino Alcohols from O-Acylated Cyanohydrins - Expanding the Scope of Minor Enantiomer Recycling. Journal of Organic Chemistry, 80(5), 2937-2941
Open this publication in new window or tab >>Synthesis of the beta(3)-Adrenergic Receptor Agonist Solabegron and Analogous N-(2-Ethylamino)-beta-amino Alcohols from O-Acylated Cyanohydrins - Expanding the Scope of Minor Enantiomer Recycling
2015 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 80, no 5, p. 2937-2941Article in journal (Refereed) Published
Abstract [en]

A novel methodology to produce highly enantioenriched N-(2-ethylamino)-beta-amino alcohols was developed. These compounds were obtained from O-(alpha-bromoacyl) cyanohydrins, which were synthesized by the minor enantiomer methodology employing a Lewis acid and a biocatalyst, followed by nucleophilic substitution with amines and reduction. The importance of the developed methodology was demonstrated by completing a highly enantioselective total synthesis of the beta(3)-adrenergic receptor agonist Solabegron.

National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-163973 (URN)10.1021/acs.joc.5b00322 (DOI)000350841600054 ()25689345 (PubMedID)2-s2.0-84924326489 (Scopus ID)
Funder
Swedish Research Council, 621-2012-3391
Note

QC 201504507

Available from: 2015-05-07 Created: 2015-04-13 Last updated: 2017-12-04Bibliographically approved
Hertzberg, R., Wen, Y.-Q. & Moberg, C. (2014). Dual activation and minor enantiomer recycling: Asymmetric synthesis of O-acylated cyanohydrins and hydroxyphosphonates. Paper presented at 248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA. Abstract of Papers of the American Chemical Society, 248
Open this publication in new window or tab >>Dual activation and minor enantiomer recycling: Asymmetric synthesis of O-acylated cyanohydrins and hydroxyphosphonates
2014 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal, Meeting abstract (Refereed) Published
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-161994 (URN)000349167402581 ()
Conference
248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA
Note

QC 20150330

Available from: 2015-03-30 Created: 2015-03-20 Last updated: 2017-12-04Bibliographically approved
Wen, Y.-Q., Hertzberg, R. & Moberg, C. (2014). Enantioselective Acylphosphonylation-Dual Lewis Acid-Lewis Base Activation of Aldehyde and Acylphosphonate. Journal of Organic Chemistry, 79(13), 6172-6178
Open this publication in new window or tab >>Enantioselective Acylphosphonylation-Dual Lewis Acid-Lewis Base Activation of Aldehyde and Acylphosphonate
2014 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 79, no 13, p. 6172-6178Article in journal (Refereed) Published
Abstract [en]

Acetoxyphosphonates were obtained by a one-step procedure consisting of reaction of diethyl acetylphosphonate with prochiral aldehydes in the presence of a catalytic system comprising a chiral Lewis acid, an achiral Lewis base, and a Bronstedt base. Best results were obtained using a tridentate Schiff base aluminum(III) Lewis acidic complex, 1H-1,2,3-benzotriazole, and a tertiary amine such as DBU. The target compounds were in most cases obtained in high yields, but with moderate enantiomeric ratios (up to 78:22).

Keywords
Aldehydes, Complexation, Functional groups, Acylphosphonate, Catalytic system, Chiral Lewis acid, Enantiomeric ratio, Enantioselective, Prochiral aldehydes, Target compound, Tridentate Schiff-base
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-148610 (URN)10.1021/jo500895u (DOI)000338693300026 ()2-s2.0-84903717843 (Scopus ID)
Funder
Wenner-Gren FoundationsSwedish Research Council, 621-2012-3391
Note

QC 20140811

Available from: 2014-08-11 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
Laurell Nash, A. & Moberg, C. (2014). Minor enantiomer recycling - CO2 formation as the driving force. Paper presented at 248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA. Abstract of Papers of the American Chemical Society, 248
Open this publication in new window or tab >>Minor enantiomer recycling - CO2 formation as the driving force
2014 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal, Meeting abstract (Other academic) Published
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-161997 (URN)000349167402798 ()
Conference
248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA
Note

QC 20150330

Available from: 2015-03-30 Created: 2015-03-20 Last updated: 2017-12-04Bibliographically approved
Wen, Y.-Q., Hertzberg, R., Gonzalez, I. & Moberg, C. (2014). Minor Enantiomer Recycling: Application to Enantioselective Syntheses of Beta Blockers. Chemistry - A European Journal, 20(13), 3806-3812
Open this publication in new window or tab >>Minor Enantiomer Recycling: Application to Enantioselective Syntheses of Beta Blockers
2014 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, no 13, p. 3806-3812Article in journal (Refereed) Published
Abstract [en]

Continuous recycling of the minor product enantiomer obtained from the acetylcyanation of prochiral aldehydes provided access to highly enantiomerically enriched products. Cyanohydrin derivatives, which under normal conditions are obtained with modest or poor enantiomeric ratios, were formed with high enantiomeric purity by using a reinforcing combination of a chiral Lewis acid catalyst and a biocatalyst. The primarily obtained products were transformed into -adrenergic antagonists (S)-propanolol, (R)-dichloroisoproterenol, and (R)-pronethalol by means of a two-step procedure.

Keywords
aldehydes, beta blockers, biocatalysis, enantioselectivity, Lewis acids
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-144946 (URN)10.1002/chem.201303890 (DOI)000332757100031 ()2-s2.0-84925284985 (Scopus ID)
Funder
Swedish Research Council, 621-2012-3391
Note

QC 20140505

Available from: 2014-05-05 Created: 2014-05-05 Last updated: 2017-05-30Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1743-7650

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