Dehydrogenation of Nitrogen Heterocycles Using Graphene Oxide as a Versatile Metal-Free Catalyst under Air
作者:Jingyu Zhang、Shiya Chen、Fangfang Chen、Wensheng Xu、Guo-Jun Deng、Hang Gong
DOI:10.1002/adsc.201700178
日期:2017.7.17
Graphene oxide (GO) has been developed as an inexpensive, environmental friendly, metal‐free carbocatalyst for the dehydrogenation of nitrogenheterocycles. Valuable compounds, such as quinoline, 3,4‐dihydroisoquinoline, quinazoline, and indole derivatives, have been successfully used as substrates. The investigation of various oxygen‐containing molecules with different conjugated systems indicated
Catalytic Asymmetric Allylboration of Indoles and Dihydroisoquinolines with Allylboronic Acids: Stereodivergent Synthesis of up to Three Contiguous Stereocenters
作者:Rauful Alam、Colin Diner、Sybrand Jonker、Lars Eriksson、Kálmán J. Szabó
DOI:10.1002/anie.201608605
日期:2016.11.7
The catalyticasymmetric allylboration of cyclic imines with γ,γ‐disubstituted allylboronic acids provides products with adjacent stereocenters in high yield and stereoselectivity. Various electrophiles, including 3,4‐dihydroisoquinolines and indoles, were prenylated in a fully stereodivergent fashion by switching the E/Z geometry of the allylboronate and/or the enantiomer of the BINOL catalyst. 3‐Methylindole
Magnesium-Promoted Additions of Difluoroenolates to Unactivated Imines
作者:Alex L. Nguyen、Hari R. Khatri、James R. Woods、Cassidy S. Baldwin、Frank R. Fronczek、David A. Colby
DOI:10.1021/acs.joc.7b03014
日期:2018.3.16
produce fluorinated and trifluoromethylated organic structures, the construction of difluoromethylated compounds remains a synthetic challenge. We have discovered that unactivated imines will react with difluoroenolates under exceedingly mild conditions when using magnesium salts and organic bases. We have applied this approach to the iminoaldol reaction to produce difluoromethylene groups as α,α-dif