Intermolecular [5 + 1]-Cycloaddition between Vinyl Diazo Compounds and <i>tert</i>-Butyl Nitrite to 1,2,3-Triazine 1-Oxides and Their Further Transformation to Isoxazoles
作者:Luca De Angelis、Haifeng Zheng、Matthew T. Perz、Hadi Arman、Michael P. Doyle
DOI:10.1021/acs.orglett.1c02352
日期:2021.8.20
1,2,3-Triazine 1-oxides are formed by nitrosyl addition from tert-butyl nitrite to the vinylogous position of vinyl diazo compounds. This transformation, which is a formal intermolecular [5 + 1] cycloaddition, occurs under mild conditions, with high functional group tolerance and regioselectivity, and can be employed for late-stage functionalization. Upon heating at refluxing chlorobenzene temperature
A convenient one-pot synthesis of 5-carboxyisoxazoles: trichloromethyl group as a carboxyl group precursor
作者:Marcos A.P. Martins、Alex F.C. Flores、Giovani P. Bastos、Adilson Sinhorin、Helio G. Bonacorso、Nilo Zanatta
DOI:10.1016/s0040-4039(99)02047-x
日期:2000.1
The one-pot synthesis of ten 5-carboxyisoxazoles from the cyclocondensation of beta-alkoxyvinyl trichloromethyl ketones [CCl3C(O)C(R-2)=C(R-1)OR, where R-1, R-2=H, Me and R=Me, Et] and 2-trichloroacetyl cyclohexanone with hydroxylamine is reported. This work shows that the trichloromethyl group attached to beta-alkoxyvinyl trichloromethyl ketones (a heterocyclic CCC building block) is an excellent carboxyl group precursor. (C) 2000 Elsevier Science Ltd. All rights reserved.