Me3SiBr-mediated intramolecular cyclization of γ-functionalized trimethylsilyl nitronates
作者:Alexander A Tishkov、Anton V Kozintsev、Il'ya M Lyapkalo、Sema L Ioffe、Vadim V Kachala、Yuri A Strelenko、Vladimir A Tartakovsky
DOI:10.1016/s0040-4039(99)00985-5
日期:1999.7
The silylation of nitro compounds of general formula X1X2CHCH(Ar)CH2NO2 with at −30°C leads to hitherto unknown 2-(N,N-bis(trimethylsilyloxy)amino-2,3-dihydrofurans (X1=PhCO, X2=H) or to N,N-bis(trimethylsilyloxy)aminocyclopropanes (X1=X2=COOMe). N,N-Bis(trimethylsilyloxy)immonium cations appear to be the key intermediates in this process.
的通式X的硝基化合物甲硅烷基化1 X 2 CHCH(Ar)的CH 2 NO 2与在-30℃通入迄今未知的2-(Ñ,Ñ双(三甲基甲硅烷基)氨基-2,3-二氢呋喃(X 1 = PhCO,X 2 = H)或N,N-双(三甲基甲硅烷氧基)氨基环丙烷(X 1 = X 2 = COOMe)N,N-双(三甲基甲硅烷氧基)铵阳离子似乎是该过程中的关键中间体。
Michael Additions Catalyzed by Metal(II) Complexes
作者:Ken-ichi Watanabe、Ken-ichi Miyazu、Kazuo Irie
DOI:10.1246/bcsj.55.3212
日期:1982.10
Michael-addition reactions have been found to proceed in the presence of the Ni(OAc)2 or Co(OAc)2-2,2′-bipyridine complex in DMF under neutral conditions at room temperature without any by-product. The reactions of chalcone and its derivatives with nitromethane generally gave good results. The effects of metal(II) ions, ligands, counter ions, and solvents on the catalysis were examined, and the features of the
Highly Enantioselective Synthesis of γ-Nitro Heteroaromatic Ketones in a Doubly Stereocontrolled Manner Catalyzed by Bifunctional Thiourea Catalysts Based on Dehydroabietic Amine: A Doubly Stereocontrolled Approach to Pyrrolidine Carboxylic Acids
作者:Xianxing Jiang、Yifu Zhang、Albert S. C. Chan、Rui Wang
DOI:10.1021/ol8025268
日期:2009.1.1
class of dehydroabietic amine-substituted primary amine-thiourea bifunctional catalysts were designed and synthesized. The doubly stereocontrolled organocatalytic conjugateaddition of a variety of heterocycles-bearing ketones to nitroalkenes was investigated for the first time, affording (S)- or (R)-γ-nitro heteroaromatic ketones with excellent enantioselectivities (up to ee >99%). Furthermore, the nearly
Michael Addition Catalyzed by Potassium Hydroxide Under Ultrasound
作者:Ji-Tai Li、Yong Cui、Guo-Feng Chen、Zhao-Li Cheng、Tong-Shuang Li
DOI:10.1081/scc-120015762
日期:2003.1.3
Abstract Michael addition of chalcone with active methylene compound such as diethyl malonate, nitromethane and ethyl acetoacetate catalyzed by potassiumhydroxide in anhydrous ethanol results Michael adducts in 75–98% yield under ultrasound irradiation in 25–90 min.
Natural Phosphate Modified with Lithium Nitrate: A New Efficient Catalyst for the Construction of Carbon–Carbon, Carbon–Sulfur, and Carbon–Nitrogen Bonds
of small amounts of lithium nitrate to natural phosphate followed by calcination gives a new catalyst Li/NP (weight ratio LiNO3/NP = 1/15). This material showed catalytic activity in the Michael addition of amines, mercaptans, and activemethylenecompounds to chalcone derivatives with high yields under mild reaction conditions. Li/NP is used as the catalyst for a facile synthesis of β-amino acids,