Palladium-Catalyzed Diastereo- and Enantioselective Formal [3 + 2]-Cycloadditions of Substituted Vinylcyclopropanes
作者:Barry M. Trost、Patrick J. Morris、Simon J. Sprague
DOI:10.1021/ja309003x
日期:2012.10.24
We describe a palladium-catalyzeddiastereo- and enantioselectiveformal [3 + 2]-cycloaddition between substituted vinylcyclopropanes and electron-deficient olefins in the form of azlactone- and Meldrum's acid alkylidenes to give highly substitutedcyclopentane products. By modulation of the electronic properties of the vinylcyclopropane and the electron-deficient olefin, high levels of stereoselectivity
Efficient and Regioselective Synthesis of Novel Functionalized Dispiropyrrolidines and Their Cytotoxic Activities
作者:Jin-Ming Yang、Yu Hu、Qiang Li、Fan Yu、Jian Cao、Dong Fang、Zhi-Bin Huang、Da-Qing Shi
DOI:10.1021/co400096c
日期:2014.3.10
An efficient and regioselective synthesis of novel functionalized dispiropyrrolizidine derivatives via a three-component [3 + 2] cycloaddition reaction of azomethineylides is described. This protocol has the advantages of high efficiency, mild reaction conditions, a one-pot procedure, and convenient operation. Many of these compounds were evaluated for their antiproliferative properties in vitro against
Enantioselective One-Pot Synthesis of α-Amino Esters by a Phosphine-Catalyzed [3+2]-Cycloaddition Reaction
作者:Marianne Steurer、Kim L. Jensen、Dennis Worgull、Karl Anker Jørgensen
DOI:10.1002/chem.201103502
日期:2012.1.2
Phosphines go one‐pot: The one‐pot synthesis of cyclic α‐amino esters from azlactones and allenes by a phosphine‐catalyzed [3+2]‐cycloaddition reaction followed by a ring opening of the azlactone moiety is presented. The products are isolated as single regioisomers in good overall yields and high enantioselectivities (up to 95 % ee). The possibility for easy modifications of the obtained products was
Synthesis of 1,2-diaminotruxinic δ-cyclobutanes by BF<sub>3</sub>-controlled [2 + 2]-photocycloaddition of 5(4<i>H</i>)-oxazolones and stereoselective expansion of δ-cyclobutanes to give highly substituted pyrrolidine-2,5-dicarboxylates
作者:Sonia Sierra、Rosa López、Enrique Gómez-Bengoa、Larry R. Falvello、Esteban P. Urriolabeitia
DOI:10.1039/d3ob00284e
日期:——
(465 nm) in the presence of the photosensitizer [Ru(bpy)3](BF4)2 (2.5 mol%) and the Lewisacid BF3·OEt2 (2 equiv.) in deoxygenated methanol at room temperature affords the corresponding 1,2-diaminotruxinic cyclobutane bis-amino esters 2a–2u stereoselectively as the δ-isomer. Characterization of cyclobutanes 2 shows that the photocycloaddition takes place by the coupling of two Z-oxazolones in a head-to-head