Expanding Dendrons. The Photoisomerism of Folded Azobenzene Dendrons
摘要:
Irradiation of a folded azobenzene dendron system triggers a large, reversible structural expansion. The dendrons adopt a compact helical conformation in the stable E form owing to the E geometry of azo linkage and the syn-syn preference of the dendritic branch points. E --> Z photoisomerization disrupts this folded conformation in a manner that decreases the packing efficiency and results in an expansion in hydrodynamic volume.
Synthesis of Structurally Diverse Benzotriazoles via Rapid Diazotization and Intramolecular Cyclization of 1,2‐Aryldiamines
作者:Réka J. Faggyas、Nikki L. Sloan、Ned Buijs、Andrew Sutherland
DOI:10.1002/ejoc.201900463
日期:2019.9
mild conditions, using a polymer‐supported nitrite reagent and p‐tosic acid. The functional group tolerance of this approach was further demonstrated with effective activation and cyclization of N‐alkyl, ‐aryl, and ‐acyl ortho‐aminoanilines leading to the synthesis of N1‐substituted benzotriazoles. The synthetic utility of this one‐pot heterocyclization process was exemplified with the preparation of a
Visible-Light-Mediated Nitration of Protected Anilines
作者:Simon J. S. Düsel、Burkhard König
DOI:10.1021/acs.joc.7b03260
日期:2018.3.2
The photocatalytic nitration of protected anilines proceeds with riboflavin tetraacetate as an organic photoredox catalyst. Sodium nitrite serves as the NO2 source in this visible-light-driven room temperature reaction. Various nitroanilines are obtained in moderate to good yields without the addition of acid or stoichiometric oxidation agents. The catalytic cycle is closed by aerial oxygen as the
Microwave-Assisted Reductive Cyclization of <i>N</i>-Allyl 2-Nitroanilines: A New Approach to Substituted 1,2,3,4-Tetrahydroquinoxalines
作者:Uwe Beifuss、Elena Merisor、Jürgen Conrad、Sabine Mika
DOI:10.1055/s-2007-984884
日期:——
N-Allyl 2-nitrophenyl amines can be efficiently cyclized to yield alkenyl-1,2,3,4-tetrahydroquinoxalines in a single reaction step by means of a new microwave-assisted reductive domino process.
Thermal decomposition of alkyl <i>N</i>-(<i>o</i>-nitrophenyl)carbamates: A novel synthesis of benzofurazan
作者:J. M. Prokipcak、P. A. Forte、D. D. Lennox
DOI:10.1139/v69-405
日期:1969.7.1
Several alkyl N-(o-nitrophenyl)carbamates have been shown to undergo thermal breakdown to give benzofurazan with the methyl derivative giving the optimum results.
Pd-Catalyzed Regioselective Intramolecular Allylic C–H Amination of 1,1-Disubstituted Alkenyl Amines
作者:Young Ho Kim、Dong Bin Kim、Su San Jang、So Won Youn
DOI:10.1021/acs.joc.2c00781
日期:2022.6.3
Pd-Catalyzed intramolecular allylic C–H amination of 1,1-disubstituted alkenyl amines with various allylic tethers (X = O, NMs, CH2) was developed. This process allows for the divergent synthesis of 1,3-X,N-heterocycles through a regioselective allylic C–H cleavage and π-allylpalladium formation. Particularly noteworthy is the use of substrates containing a labile allylic moiety and new simple catalytic