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Biswas, Srijit
Publications (8 of 8) Show all publications
Bunrit, A., Watile, R., Dahlstrand, C., Olsson, S., Srifa, P., Huang, G., . . . Samec, J. (2017). H3PO2-catalyzed intramolecular stereospecific nucleophilic substitution of the hydroxyl group in stereogenic alcohols. Paper presented at 254th National Meeting and Exposition of the American-Chemical-Society (ACS) on Chemistry's Impact on the Global Economy, AUG 20-24, 2017, Washington, DC. Abstract of Papers of the American Chemical Society, 254
Open this publication in new window or tab >>H3PO2-catalyzed intramolecular stereospecific nucleophilic substitution of the hydroxyl group in stereogenic alcohols
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2017 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 254Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-357070 (URN)000429556701849 ()
Conference
254th National Meeting and Exposition of the American-Chemical-Society (ACS) on Chemistry's Impact on the Global Economy, AUG 20-24, 2017, Washington, DC
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-08-13Bibliographically approved
Biswas, S., Watile, R. A. & Samec, J. S. M. (2014). Tandem Pd/Au-Catalyzed Route to alpha-Sulfenylated Carbonyl Compounds from Terminal Propargylic Alcohols and Thiols. Chemistry - A European Journal, 20(8), 2159-2163
Open this publication in new window or tab >>Tandem Pd/Au-Catalyzed Route to alpha-Sulfenylated Carbonyl Compounds from Terminal Propargylic Alcohols and Thiols
2014 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, no 8, p. 2159-2163Article in journal (Refereed) Published
Abstract [en]

An efficient and highly atom-economical tandem Pd/Au-catalyzed route to -sulfenylated carbonyl compounds from terminal propargylic alcohols and thiols has been developed. This one-step procedure has a wide substrate scope with respect to substituents at the -position of the alcohol. Both aromatic and aliphatic thiols generated the -sulfenylated carbonyl products in good to excellent yields. A mechanism is proposed in which the reaction proceeds through a Pd-catalyzed regioselective hydrothiolation at the terminal triple bond of the propargyl alcohol followed by an Au-catalyzed 1,2-hydride migration.

Keywords
atom efficiency, gold, palladium, sulfenylated carbonyl, tandem catalysis
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-222173 (URN)10.1002/chem.201304111 (DOI)000330903700007 ()
Available from: 2014-04-10 Created: 2014-04-08 Last updated: 2017-12-05Bibliographically approved
Watile, R., Biswas, S. & Samec, J. (2013). An aqueous and recyclable copper(I)-catalyzed route to α-sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols. Green Chemistry, 15(11), 3176-3179
Open this publication in new window or tab >>An aqueous and recyclable copper(I)-catalyzed route to α-sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols
2013 (English)In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 15, no 11, p. 3176-3179Article in journal (Refereed) Published
Abstract [en]

A highly efficient one-step copper(I)-catalyzed method for the synthesis of α-sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols in aqueous media is described. A variety of α-sulfenylated carbonyl compounds can be synthesized in good to excellent yields. The catalyst has been successfully recycled up to 4 times without any loss of activity in an aqueous medium.

National Category
Natural Sciences
Research subject
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-207551 (URN)10.1039/C3GC41251B (DOI)000327052700024 ()
Available from: 2013-09-16 Created: 2013-09-16 Last updated: 2017-12-06Bibliographically approved
Biswas, S., Dahlstrand, C., Watile, R. A., Kalek, M., Himo, F. & Samec, J. S. M. (2013). Atom-Efficient Gold(I)-Chloride-Catalyzed Synthesis of alpha-Sulfenylated Carbonyl Compounds from Propargylic Alcohols and Aryl Thiols: Substrate Scope and Experimental and Theoretical Mechanistic Investigation. Chemistry - A European Journal, 19(52), 17939-17950
Open this publication in new window or tab >>Atom-Efficient Gold(I)-Chloride-Catalyzed Synthesis of alpha-Sulfenylated Carbonyl Compounds from Propargylic Alcohols and Aryl Thiols: Substrate Scope and Experimental and Theoretical Mechanistic Investigation
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2013 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, no 52, p. 17939-17950Article in journal (Refereed) Published
Abstract [en]

Gold(I)-chloride-catalyzed synthesis of -sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols showed a wide substrate scope with respect to both propargylic alcohols and aryl thiols. Primary and secondary aromatic propargylic alcohols generated -sulfenylated aldehydes and ketones in 60-97% yield. Secondary aliphatic propargylic alcohols generated -sulfenylated ketones in yields of 47-71%. Different gold sources and ligand effects were studied, and it was shown that gold(I) chloride gave the highest product yields. Experimental and theoretical studies demonstrated that the reaction proceeds in two separate steps. A sulfenylated allylic alcohol, generated by initial regioselective attack of the aryl thiol on the triple bond of the propargylic alcohol, was isolated, evaluated, and found to be an intermediate in the reaction. Deuterium labeling experiments showed that the protons from the propargylic alcohol and aryl thiol were transferred to the 3-position, and that the hydride from the alcohol was transferred to the 2-position of the product. Density functional theory (DFT) calculations showed that the observed regioselectivity of the aryl thiol attack towards the 2-position of propargylic alcohol was determined by a low-energy, five-membered cyclic protodeauration transition state instead of the strained, four-membered cyclic transition state found for attack at the 3-position. Experimental data and DFT calculations supported that the second step of the reaction is initiated by protonation of the double bond of the sulfenylated allylic alcohol with a proton donor coordinated to gold(I) chloride. This in turn allows for a 1,2-hydride shift, generating the final product of the reaction.

Keywords
gold, homogeneous catalysis, reaction mechanisms, sulfenylation, synthetic methods
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-215902 (URN)10.1002/chem.201302485 (DOI)000328531000036 ()
Available from: 2014-01-17 Created: 2014-01-17 Last updated: 2017-12-06Bibliographically approved
Biswas, S. & Samec, J. S. M. (2013). Gold-catalyzed route to alpha-sulfenylated carbonyl compounds from propargylic alcohols and thiophenol: Scope, limitations, and mechanism. Paper presented at 245th National Spring Meeting of the American-Chemical-Society (ACS), APR 07-11, 2013, New Orleans, LA, USA. Abstract of Papers of the American Chemical Society, 245, 382-ORGN
Open this publication in new window or tab >>Gold-catalyzed route to alpha-sulfenylated carbonyl compounds from propargylic alcohols and thiophenol: Scope, limitations, and mechanism
2013 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245, p. 382-ORGN-Article in journal, Meeting abstract (Other academic) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-210334 (URN)000324303603061 ()
Conference
245th National Spring Meeting of the American-Chemical-Society (ACS), APR 07-11, 2013, New Orleans, LA, USA
Available from: 2013-11-06 Created: 2013-11-05 Last updated: 2017-12-06Bibliographically approved
Biswas, S. & Samec, J. (2013). The Efficiency of the Metal Catalysts in the Nucleophilic Substitution of Alcohols is Dependent on the Nucleophile and Not on the Electrophile. Chemistry - An Asian Journal, 8(5), 974-981
Open this publication in new window or tab >>The Efficiency of the Metal Catalysts in the Nucleophilic Substitution of Alcohols is Dependent on the Nucleophile and Not on the Electrophile
2013 (English)In: Chemistry - An Asian Journal, ISSN 1861-4728, E-ISSN 1861-471X, Vol. 8, no 5, p. 974-981Article in journal (Refereed) Published
Abstract [en]

In this study, we investigate the effect of the electrophiles and the nucleophiles for eight catalysts in the catalytic SN1 type substitution of alcohols with different degree of activation by sulfur-, carbon-, oxygen-, and nitrogen-centered nucleophiles. The catalysts do not show any general variance in efficiency or selectivity with respect to the alcohols and follow the trend of alcohol reactivity. However, when it comes to the nucleophile, the eight catalysts show general and specific variances in the efficiency and selectivity to perform the desired substitution. Interestingly, the selectivity of the alcohols to produce the desired substitution products was found to be independent of the electrophilicity of the generated carbocations but highly dependent on the ease of formation of the cation. Catalysts based on iron(III), bismuth(III), and gold(III) show higher conversions for S-, C-, and N-centered nucleophiles, and BiIII was the most efficient catalyst in all combinations. Catalysts based on rhenium(I) or rhenium(VII), palladium(II), and lanthanum(III) were the most efficient in performing the nucleophilic substitution on the various alcohols with the O-centered nucleophiles. These catalysts generate the symmetrical ether as a by-product from the reactions of S-, C-, and N-centered nucleophiles as well, resulting in lower chemoselectivity.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-196660 (URN)10.1002/asia.201201178 (DOI)000318235400018 ()
Available from: 2013-03-12 Created: 2013-03-12 Last updated: 2017-12-06Bibliographically approved
Biswas, S. & Samec, J. (2012). A Gold(I)-Catalyzed Route to α-Sulfenylated Carbonyl Compounds from Propargylic Alcohols and Aryl Thiols. Chemical Communications, 48(52), 6586-6588
Open this publication in new window or tab >>A Gold(I)-Catalyzed Route to α-Sulfenylated Carbonyl Compounds from Propargylic Alcohols and Aryl Thiols
2012 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 48, no 52, p. 6586-6588Article in journal (Refereed) Published
Abstract [en]

A one-step atom efficient gold(I)-catalyzed route to α-sulfenylated ketones and aldehydes from propargylic alcohols and aryl thiols is described.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-174529 (URN)10.1039/C2CC32042H (DOI)000304883000040 ()
Available from: 2012-05-21 Created: 2012-05-21 Last updated: 2017-12-07Bibliographically approved
Mirzaei, A., Biswas, S. & Samec, J. (2012). Iron(III)-Catalyzed Nucleophilic Substitution of the Hydroxy Group in Benzoin by Alcohols. Synthesis (Stuttgart), 44(8), 1213-1218
Open this publication in new window or tab >>Iron(III)-Catalyzed Nucleophilic Substitution of the Hydroxy Group in Benzoin by Alcohols
2012 (English)In: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, Vol. 44, no 8, p. 1213-1218Article in journal (Refereed) Published
Abstract [en]

The etherification reaction between benzoin derivatives and alcohols catalyzed by iron(III) proceeds in moderate to good yields. Other metal complexes showed either low reactivity or low chemoselectivity where oxidation of benzoin to benzil was a competing reaction. The iron source operated as a catalyst where 5 mol% of iron(III) generate the 2-alkoxy-1,2-diphenylethan-1-one in 50% yield. With an optimum of 25 mol% of catalyst, the desired ether was obtained in 85% yield. The etherification of benzoin and an alcohol proceed to generate the desired product in polar solvents such as 1,2-dichloroethane, whereas less polar solvents promote the competing oxidation to generate the benzil; polar coordinating solvents such as tetrahydrofuran inhibited the reaction. The efficiency of the reaction is found to be dependent on nucleophile where an optimum of 30 equivalents of alcohol was observed. With electron-­donating substituents on the aromatic ring, the etherification was followed by oxidation to generate the benzil. Moderate yields of etherification product were obtained by monitoring the reaction progress with electron-rich substrates and quenching the reaction after two hours.

Keywords
iron catalysis, Lewis acids, substitution, ethers, alcohols
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-174530 (URN)10.1055/s-0031-1289738 (DOI)000303104400012 ()
Available from: 2012-05-21 Created: 2012-05-21 Last updated: 2017-12-07Bibliographically approved
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