Cycloadditions of Noncomplementary Substituted 1,2,3-Triazines
作者:Erin D. Anderson、Adam S. Duerfeldt、Kaicheng Zhu、Christopher M. Glinkerman、Dale L. Boger
DOI:10.1021/ol502436n
日期:2014.10.3
The scope of the [4 + 2] cycloadditionreactions of substituted 1,2,3-triazines, bearing noncomplementary substitution with electron-withdrawing groups at C4 and/or C6, is described. The studies define key electronic and stericeffects of substituents impacting the reactivity, mode (C4/N1 vs C5/N2), and regioselectivity of the cycloadditionreactions of 1,2,3-triazines with amidines, enamines, and
Asymmetric Hydrogenation of Unfunctionalized Enamines Catalyzed by Iridium Complexes of Chiral Spiro N,N-Diarylphosphoramidites
作者:Pucha Yan、Jianhua Xie、Qilin Zhou
DOI:10.1002/cjoc.201090293
日期:2010.9
Chiral spiro N,N‐diarylphosphoramidites were synthesized. These new chiral spiro monophosphoramidites were efficient ligands for iridium‐catalyzedasymmetrichydrogenation of unfunctionalized enamines derived from simple alkyl aryl ketones, providing chiral tertiary amines in good enantioselectivities (up to 90% ee).
4-Dimethylamino-1-trifluoracetyl-pyridinium-trifluoracetat: Ein effizientes Reagens zur Synthese von Trifluormethyl-1,3-dicarbonyl-Verbindungen
作者:Gerhard Simchen、Andreas Schmidt
DOI:10.1055/s-1997-1501
日期:1997.1
4-Dimethylamino-1-trifluoroacetylpyridinium Trifluoroacetat: An Efficient Reagent for the Preparation of Trifluoromethyl-1,3-Dicarbonyl CompoundsEnamines 2 and O-trimethylsilyl ketene acetals 4 are trifluoroacetylated on reaction with the title reagent to yield trifluoroacetyl enamines 3 and trifluoromethylsilylenol ethers 5, respectively. Trifluoromethyl 1,3-diketones 6 and trifluoromethyl β-keto esters 7 are obtained by hydrolysis of compounds 3 and 5.
Synthesis of aromatic 1,2-diazines by inverse electron demand Diels-Alder reaction of polymer-supported 1,2,4,5-tetrazines
作者:James S. Panek、Bin Zhu
DOI:10.1016/0040-4039(96)01866-7
日期:1996.11
InverseelectrondemandDiels-Alderreactions of unsymmetrically substituted 1,2,4,5-tetrazines immobilized on a solid support participate in thermally promoted cycloadditions with a wide range of electron-rich dienophiles. The reactions afford functionalized 1,2-diazines bearing a sulfur-based leaving group (-SR or -SO2R) at the C-6 position.