Enantioselective ene-reduction of E-2-cyano-3-(furan-2-yl) acrylamide by marine and terrestrial fungi and absolute configuration of (R)-2-cyano-3-(furan-2-yl) propanamide determined by calculations of electronic circular dichroism (ECD) spectra.

Autor: Jimenez DEQ; Departamento de Química, Universidade Federal do Amapá, Macapá, Brazil.; Laboratório de Química Orgânica e Biocatálise, Instituto de Química de São Carlos, Universidade de São Paulo - USP, São Carlos, Brazil., Barreiro JC; Laboratório de Química Orgânica e Biocatálise, Instituto de Química de São Carlos, Universidade de São Paulo - USP, São Carlos, Brazil., Dos Santos FM Jr; Departamento de Química Orgânica, Instituto de Química, Universidade Federal Fluminense, Niterói, Brazil., de Vasconcellos SP; Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo-UNIFESP, Diadema, Brazil., Porto ALM; Laboratório de Química Orgânica e Biocatálise, Instituto de Química de São Carlos, Universidade de São Paulo - USP, São Carlos, Brazil., Batista JM Jr; Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo-UNIFESP, São José dos Campos, Brazil.
Jazyk: angličtina
Zdroj: Chirality [Chirality] 2019 Jul; Vol. 31 (7), pp. 534-542. Date of Electronic Publication: 2019 Jun 13.
DOI: 10.1002/chir.23078
Abstrakt: This work reports the green organic chemistry synthesis of E-2-cyano-3(furan-2-yl) acrylamide under microwave radiation (55 W), as well as the use of filamentous marine and terrestrial-derived fungi, in the first ene-reduction of 2-cyano-3-(furan-2-yl) acrylamide to (R)-2-cyano-3-(furan-2-yl)propanamide. The fungal strains screened included Penicillium citrinum CBMAI 1186, Trichoderma sp. CBMAI 932 and Aspergillus sydowii CBMAI 935, and the filamentous terrestrial fungi Aspergillus sp. FPZSP 146 and Aspergillus sp. FPZSP 152. A compound with an uncommon CN-bearing stereogenic center at the α-C position was obtained by enantioselective reactions mediated in the presence of the microorganisms yielding the (R)-2-cyano-3-(furan-2-yl) propanamide 3a. Its isolated yield and e.e. ranged from 86% to 98% and 39% to 99%, respectively. The absolute configuration of the biotransformation products was determined by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. Finally, the tautomerization of 2-cyano-3-(furan-2-yl) propanamide 3a to form an achiral ketenimine was observed and investigated in presence of protic solvents.
(© 2019 Wiley Periodicals, Inc.)
Databáze: MEDLINE
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