Cascade Cleavage of Three-Membered Rings in the Reaction of D-A Cyclopropanes with 4,5-Diazaspiro[2.4]hept-4-enes: A Route to Highly Functionalized Pyrazolines.

Autor: Novikov RA; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation.; Engelhardt Institute of Molecular Biology, Russian Academy of Sciences , 32 Vavilov st. , 119991 Moscow , Russian Federation., Borisov DD; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation., Zotova MA; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation., Denisov DA; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation., Tkachev YV; Engelhardt Institute of Molecular Biology, Russian Academy of Sciences , 32 Vavilov st. , 119991 Moscow , Russian Federation., Korolev VA; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation., Shulishov EV; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation., Tomilov YV; N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , 47 Leninsky prosp. , 119991 Moscow , Russian Federation.
Jazyk: angličtina
Zdroj: The Journal of organic chemistry [J Org Chem] 2018 Aug 03; Vol. 83 (15), pp. 7836-7851. Date of Electronic Publication: 2018 Jun 22.
DOI: 10.1021/acs.joc.8b00725
Abstrakt: A new cascade process for reactions of donor-acceptor cyclopropanes (DACs) with spiro[cyclopropanepyrazolines] in the presence of EtAlCl 2 or Ga halides is reported. The action of a Lewis acid results in DAC activation and addition of the carbocationic intermediate to the azocyclopropane system of the pyrazoline with opening of the second three-membered ring and addition of a halide anion from the Lewis acid. A specific feature of this process is that one activated cyclopropane ring activates another one, and depending on the component ratio, the process can involve two DAC molecules and one pyrazoline molecule or one DAC molecule and two pyrazoline molecules. The process is tolerant to various functional groups and occurs with a wide range of substrates to give polyfunctionalized structures based on a 2-pyrazoline moiety.
Databáze: MEDLINE
Externí odkaz: