Boron Trifluoride-Mediated Cycloaddition of 3-Bromotetrazine and Silyl Enol Ethers: Synthesis of 3-Bromo-pyridazines
作者:Simon D. Schnell、Jorge A. González、Jan Sklyaruk、Anthony Linden、Karl Gademann
DOI:10.1021/acs.joc.1c01384
日期:2021.9.3
regiocontrol remains difficult. We achieved the Lewis acid-mediated inverse electron demand Diels–Alder reaction between 3-monosubstituted s-tetrazine and silylenolethers and obtained functionalized pyridazines. In the case of 1-monosubstituted silylenolethers, exclusive regioselectivity was observed. Downstream functionalization of the resulting 3-bromo-pyridazines was demonstrated utilizing several cross-coupling
WERBEL L. M.; MCNAMARA D. J.; COLBRY N. L.; JOHNSON J. L.; DEGNAN M. J.; +, J. HETEROCYCL. CHEM., 1979, 16, NO 5, 881-894
作者:WERBEL L. M.、 MCNAMARA D. J.、 COLBRY N. L.、 JOHNSON J. L.、 DEGNAN M. J.、 +
DOI:——
日期:——
Divergent Synthesis of Monosubstituted and Unsymmetrical 3,6‐Disubstituted Tetrazines from Carboxylic Ester Precursors
作者:Yixin Xie、Yinzhi Fang、Zhen Huang、Amanda M. Tallon、Christopher W. am Ende、Joseph M. Fox
DOI:10.1002/anie.202005569
日期:2020.9.21
unsymmetrical and 3‐monosubstituted tetrazines. Described here is a general, one‐pot method for converting (3‐methyloxetan‐3‐yl)methyl carboxylic esters into 3‐thiomethyltetrazines. These versatile intermediates were applied to the synthesis of unsymmetrical tetrazines through Pd‐catalyzed cross‐coupling and in the first catalytic thioether reduction to access monosubstituted tetrazines. This method enables
Nucleophilic Attack on Nitrogen in Tetrazines by Silyl-Enol Ethers
作者:Simon D. Schnell、Mauro Schilling、Jan Sklyaruk、Anthony Linden、Sandra Luber、Karl Gademann
DOI:10.1021/acs.orglett.0c04113
日期:2021.4.2
The nucleophilic addition of silyl-enol ethers to nitrogen in 3-monosubstituted s-tetrazines mediated by BF3 is reported. The preference for this azaphilic addition over the usually observed inverse electron demand Diels–Alder reactions was evaluated theoretically and corroborated by experiments. The substrate dependency of this unusual reaction was rationalized by determination of the activation barriers