Regioselective Reduction of 3-Substituted <i>N</i>-Acylpyrazinium Salts toward the Synthesis of 1,2-Dihydropyrazines
作者:Alfred L. Williams、Valentine R. St. Hilaire、Tina Lee
DOI:10.1021/jo202498r
日期:2012.4.20
The regioselectivereduction of 3-substituted N-acylpyrazinium salts with n-Bu3SnH has been developed for the synthesis of 3-substituted 1,2-dihydropyrazines in yields of 56–94%. Substitution of the pyrazinium salts with electron-donating groups favors the formation of the 1,2-isomers as a result of their better stability over the 1,6-isomers. Under mild acidic conditions, 3-methoxy substituted 1,2-dihydropyrazine
Site-Selective C–H Alkylation of Diazine <i>N</i>-Oxides Enabled by Phosphonium Ylides
作者:Prithwish Ghosh、Na Yeon Kwon、Sangil Han、Saegun Kim、Sang Hoon Han、Neeraj Kumar Mishra、Young Hoon Jung、Sang J. Chung、In Su Kim
DOI:10.1021/acs.orglett.9b02365
日期:2019.8.16
The synthesis of alkylated diazine derivatives is important for their practical utilization as pharmaceuticals and for other purposes. Herein, we describe the metal-free site-selectiveC–H alkylation of diazine N-oxides using phosphonium ylides that affords a variety of alkylated diazine derivatives with broad functional group tolerance. The utility of this method is showcased by the late-stage functionalization