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Sawant, Rajiv T.
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Publications (9 of 9) Show all publications
Sawant, R. T., Stevens, M. Y. & Odell, L. R. (2018). Microwave-Assisted aza-Friedel-Crafts Arylation of N-Acyliminium Ions: Expedient Access to 4 -Aryl 3,4-Dihydroquinazolinones. ACS OMEGA, 3(10), 14258-14265
Open this publication in new window or tab >>Microwave-Assisted aza-Friedel-Crafts Arylation of N-Acyliminium Ions: Expedient Access to 4 -Aryl 3,4-Dihydroquinazolinones
2018 (English)In: ACS OMEGA, ISSN 2470-1343, Vol. 3, no 10, p. 14258-14265Article in journal (Refereed) Published
Abstract [en]

A one-pot microwave-assisted aza-Friedel-Crafts arylation of N-acyliminium ions, generated in situ from o-formyl carbamates and different amines, is reported. This metal-free protocol provides rapid access to diverse 4-aryl 3,4-dihydroquinazolinones in excellent yield without any aqueous workup. A solvent-directed process for the selective aza-Friedel-Crafts arylation of electron-rich aryl/heteroaryl/butenyl-tethered N-acyliminium ions is also described.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Medicinal Chemistry
Identifiers
urn:nbn:se:uu:diva-369754 (URN)10.1021/acsomega.8b02298 (DOI)000449026500209 ()
Available from: 2018-12-18 Created: 2018-12-18 Last updated: 2018-12-18Bibliographically approved
Sawant, R. T., Stevens, M. Y. & Odell, L. R. (2017). Acetic acid-promoted cascade N-acyliminium ion/aza-Prins cyclization: stereoselective synthesis of functionalized fused tricyclic piperidines. Chemical Communications, 53(13), 2110-2113
Open this publication in new window or tab >>Acetic acid-promoted cascade N-acyliminium ion/aza-Prins cyclization: stereoselective synthesis of functionalized fused tricyclic piperidines
2017 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 13, p. 2110-2113Article in journal (Refereed) Published
Abstract [en]

A novel acetic acid-promoted metal-free cascade N-acyliminium ion/aza-Prins cyclization of o-formyl carbamates and homoallylamines is reported. This one-pot protocol provides efficient and rapid access to masked cis-hydroxyhexahydropyrido[1,2-c] quinazolin-6-ones with concomitant generation of two stereogenic centers, four C-C/C-O/C-N bonds and two new rings in good yield and excellent diastereoselectivity.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Medicinal Chemistry
Identifiers
urn:nbn:se:uu:diva-319679 (URN)10.1039/c6cc09805c (DOI)000395625700006 ()28133651 (PubMedID)
Available from: 2017-04-07 Created: 2017-04-07 Last updated: 2018-01-13Bibliographically approved
Sawant, R. T., Stevens, M. Y., Sköld, C. & Odell, L. R. (2016). Microwave-Assisted Branching Cascades: A Route to Diverse 3,4-Dihydroquinazolinone-Embedded Polyheterocyclic Scaffolds. Organic Letters, 18(20), 5392-5395
Open this publication in new window or tab >>Microwave-Assisted Branching Cascades: A Route to Diverse 3,4-Dihydroquinazolinone-Embedded Polyheterocyclic Scaffolds
2016 (English)In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 18, no 20, p. 5392-5395Article in journal (Refereed) Published
Abstract [en]

A novel metal-free microwave-assisted branching cascades strategy for the efficient synthesis of 3,4-dihydro-quinazolinone-embedded polyheterocyclic scaffolds is reported. Starting from in situ generated key N-acyliminium ion precursors, 12 distinct and skeletally diverse polycyclic frameworks were accessed in a single step/pot via adjustment of the nucleophile(s) and reaction conditions. Postcascade functionalization of these compounds was also demonstrated, proving the utility of this method in accessing structurally diverse chemical entities.

National Category
Medicinal Chemistry
Identifiers
urn:nbn:se:uu:diva-308641 (URN)10.1021/acs.orglett.6b02774 (DOI)000386187300052 ()27726402 (PubMedID)
Available from: 2016-11-30 Created: 2016-11-29 Last updated: 2018-01-13Bibliographically approved
Sawant, R. T., Stevens, M. Y. & Odell, L. R. (2015). 3,4-Dihydro-3-(2-hydroxyethyl)-4-(nitromethyl)quinazolin-2(1H)-one. Molbank, 2015(3)
Open this publication in new window or tab >>3,4-Dihydro-3-(2-hydroxyethyl)-4-(nitromethyl)quinazolin-2(1H)-one
2015 (English)In: Molbank, ISSN 1422-8599, E-ISSN 1422-8599, Vol. 2015, no 3Article in journal (Refereed) Published
National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-263475 (URN)10.3390/M866 (DOI)
Available from: 2015-09-30 Created: 2015-09-30 Last updated: 2017-12-01
Stevens, M. Y., Wieckowski, K., Wu, P., Sawant, R. T. & Odell, L. R. (2015). A microwave-assisted multicomponent synthesis of substituted 3,4-dihydroquinazolinones. Organic and biomolecular chemistry, 13(7), 2044-2054
Open this publication in new window or tab >>A microwave-assisted multicomponent synthesis of substituted 3,4-dihydroquinazolinones
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2015 (English)In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 13, no 7, p. 2044-2054Article in journal (Refereed) Published
Abstract [en]

A microwave-assisted, multicomponent protocol for the synthesis of substituted 3,4-dihydroquinazolinones via a novel cascade imine/cyclization/aza-Henry reaction sequence is reported. Starting from o-formyl carbamates, a series of structurally diverse 3,4-dihydroquinazolinones was synthesized via a cyclic iminium ion intermediate in moderate to excellent yields. Notably, the reaction is fast, flexible, simple to perform and tolerates a variety of functional groups.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-245140 (URN)10.1039/c4ob02417f (DOI)000349401300016 ()25518892 (PubMedID)
Available from: 2015-02-25 Created: 2015-02-25 Last updated: 2017-12-04Bibliographically approved
Sawant, R. T., Stevens, M. Y. & Odell, L. R. (2015). Rapid Access to Polyfunctionalized 3,4-Dihydroquinazolinones through a Sequential N-Acyliminium Ion Mannich Reaction Cascade. European Journal of Organic Chemistry (35), 7743-7755
Open this publication in new window or tab >>Rapid Access to Polyfunctionalized 3,4-Dihydroquinazolinones through a Sequential N-Acyliminium Ion Mannich Reaction Cascade
2015 (English)In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 35, p. 7743-7755Article in journal (Refereed) Published
Abstract [en]

A microwave-promoted one-pot, three-component sequential cyclization-Mannich reaction of unactivated ketones, o-formyl carbamates and primary amines has been developed. Cyclic N-acyliminium ions are generated in situ from the carbamate and amine starting materials. This metal-free cascade protocol provides rapid access to structurally diverse 3,4-dihydroquinazolinones in good to excellent yields with high regioselectivity for the terminal methyl group, in the case of unsymmetrical methyl alkyl ketones. Key features of the developed protocol include its operational simplicity, ease of product purification, and wide functional group tolerance.

Keywords
Multicomponent reactions, Domino reactions, Nitrogen heterocycles, Mannich bases, Regioselectivity
National Category
Organic Chemistry
Research subject
Chemistry with specialization in Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-268568 (URN)10.1002/ejoc.201501178 (DOI)000366426600015 ()
Available from: 2016-02-04 Created: 2015-12-08 Last updated: 2017-11-30Bibliographically approved
Stevens, M. Y., Sawant, R. T. & Odell, L. R. (2014). Synthesis of arylsulfonyl azides via diazotransfer using an imidazole-1-sulfonyl azide salt: Scope and N-15 NMR labeling experiments. 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 >>Synthesis of arylsulfonyl azides via diazotransfer using an imidazole-1-sulfonyl azide salt: Scope and N-15 NMR labeling experiments
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
Medicinal Chemistry
Identifiers
urn:nbn:se:uu:diva-247871 (URN)000349167403500 ()
Conference
248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA
Available from: 2015-03-24 Created: 2015-03-24 Last updated: 2018-01-11Bibliographically approved
Stevens, M., Sawant, R. & Odell, L. (2014). Synthesis of sulfonyl azides via diazotransfer using an imidazole-1-sulfonyl azide salt: scope and ¹⁵N NMR labeling experiments. Journal of Organic Chemistry, 79(11), 4826-4831
Open this publication in new window or tab >>Synthesis of sulfonyl azides via diazotransfer using an imidazole-1-sulfonyl azide salt: scope and ¹⁵N NMR labeling experiments
2014 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 79, no 11, p. 4826-4831Article in journal (Refereed) Published
Abstract [en]

Imidazole-1-sulfonyl azide hydrogen sulfate is presented as an efficient reagent for the synthesis of sulfonyl azides from primary sulfonamides. The described method is experimentally simple and high-yielding and does not require the addition of Cu salts. Furthermore, 15N NMR mechanistic studies show the reaction proceeds via a diazo transfer mechanism. Imidazole-1-sulfonyl azide hydrogen sulfate provides a considerable advantage over existing diazo transfer reagents in terms of impact stability, cost, and ease of use

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2014
National Category
Organic Chemistry
Research subject
Chemistry with specialization in Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-232477 (URN)10.1021/jo500553q (DOI)000337073900006 ()
Available from: 2014-09-18 Created: 2014-09-18 Last updated: 2017-12-05Bibliographically approved
Sawant, R. T., Stevenson, J., Odell, L. R. & Arvidsson, P. I. (2013). Organocatalytic asymmetric cross-aldol reaction of 2-chloroethoxy acetaldehyde: diversity-oriented synthesis of chiral substituted 1,4-dioxanes and morpholines. Tetrahedron: asymmetry, 24(2-3), 134-141
Open this publication in new window or tab >>Organocatalytic asymmetric cross-aldol reaction of 2-chloroethoxy acetaldehyde: diversity-oriented synthesis of chiral substituted 1,4-dioxanes and morpholines
2013 (English)In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 24, no 2-3, p. 134-141Article in journal (Refereed) Published
Abstract [en]

Herein we report a facile organocatalytic asymmetric direct cross-aldol reaction of 2-chloroethoxy acetaldehyde with aromatic aldehydes using (S)-(-)-alpha,alpha-diphenyl-2-pyrrolidinemethanol as an organocatalyst to afford anti-2-(2-chloroethoxy)-1-arylpropane-1,3-diols with excellent enantioselectivities (95-98%) and moderate diastereoselectivities (3.5-7:1). The 1,3-diols, obtained after the aldehyde reduction, represent highly functional intermediates that allow for further diversification into both chiral 1,4-dioxanes and morpholines, compounds that frequently display interesting biological activities.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-197659 (URN)10.1016/j.tetasy.2012.12.004 (DOI)000315550900007 ()
Available from: 2013-04-02 Created: 2013-04-02 Last updated: 2017-12-06Bibliographically approved
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