Alkenyl Arenes as Dipolarophiles in Catalytic Asymmetric 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides
作者:Ana Pascual-Escudero、Abel de Cózar、Fernando P. Cossío、Javier Adrio、Juan C. Carretero
DOI:10.1002/anie.201609187
日期:2016.12.5
The use of alkenyl arenes as dipolarophiles in the catalytic asymmetric 1,3‐dipolarcycloaddition of azomethineylides is reported. Under appropriate reaction conditions with a CuI or AgI catalyst either the exo or the endo adduct was obtained with high stereoselectivity. This process provides efficient access to highly enantiomerically enriched 4‐aryl proline derivatives. The observed results are
Direct synthesis of pyrroles via 1,3-dipolar cycloaddition of azomethine ylides with ynones
作者:Zheng Wang、Ying Shi、Xiaoyan Luo、De-Man Han、Wei-Ping Deng
DOI:10.1039/c3nj00067b
日期:——
A direct and facile synthesis of multi-substituted pyrroles via AgOAc-catalyzed 1,3-dipolarcycloaddition of azomethine ylides with ynones is developed, providing the corresponding adducts in moderate to high yields (up to 89%).
General Enantioselective C−H Activation with Efficiently Tunable Cyclopentadienyl Ligands
作者:Zhi-Jun Jia、Christian Merten、Rajesh Gontla、Constantin G. Daniliuc、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1002/anie.201611981
日期:2017.2.20
applicable chiral Cp ligand collection (JasCp ligands) with highly variable and adjustable structures. Their modular nature and their amenability to rapid structure variation enabled the efficientdiscovery of ligands for three enantioselective RhIII‐catalyzed C−H activation reactions, including one unprecedented transformation. This novel approach should enable the discovery of efficientchiral Cp ligands
for asymmetric [3+2] cycloaddition reactions. A silver complex prepared from silver bis(trimethylsilyl)amide (AgHMDS) and (R)‐DTBM‐SEGPHOS worked well in asymmetric [3+2] cycloaddition reactions of α‐aminoester Schiff bases with several olefins to afford the corresponding pyrrolidine derivatives in high yields with remarkable exo‐ and enantioselectivities. Furthermore, α‐aminophosphonate Schiff bases
Metal Amides as the Simplest Acid/Base Catalysts for Stereoselective Carbon-Carbon Bond-Forming Reactions
作者:Yasuhiro Yamashita、Shū Kobayashi
DOI:10.1002/chem.201300908
日期:2013.7.15
paper, new possibilities for metalamides are described. Although typical metalamides are recognized as strong stoichiometric bases for deprotonation of inert or less acidic hydrogen atoms, transition‐metalamides, namely silver and copper amides, show interesting abilities as one of the simplestacid/basecatalysts in stereoselectivecarbon–carbon bond‐forming reactions.