作者:Yongzheng Qu、Zheyuan Wang、Zhongchao Zhang、Wendou Zhang、Jun Huang、Zhen Yang
DOI:10.1021/jacs.0c02143
日期:2020.4.8
The asymmetric total synthesis of (+)-waihoensene, which has a cis-fused [6,5,5,5] tetracyclic core bearing an angulartriquinane, a cis-fused six-membered ring, and four contiguous quaternary car-bon atoms, was achieved through a sequence of chemical reac-tions in a stereochemically well-defined manner. The total synthe-sis features: 1) Cu-catalyzed asymmetric conjugated 1,4-addition; 2) diastereoselective
Copper-Catalyzed Asymmetric Conjugate Addition with Chiral SimplePhos Ligands
作者:Laëtitia Palais、Alexandre Alexakis
DOI:10.1002/chem.200901577
日期:2009.10.12
they can be highly functionalised. Herein we report the copper‐catalysed asymmetricconjugateaddition of diethyl zinc and trialkylaluminium reagents with SimplePhos ligands, which gives high enantioselectivity with cyclic enones, acyclic enones and nitro‐olefins, with up to 98.6 % ee. Of particular interest is the reaction of trialkylaluminium reagents with a wide range of 3‐substituted enones, thus
Photoinduced electron transfer (PET) reactions of α-cyclopropyl-substituted ketones and triethylamine (TEA) were used to initiate the cyclopropylcarbinyl-homoallyl rearrangement. The intramolecular cyclization reaction onto triple bonds was performed yielding bicyclic and spirocyclic compounds. Furthermore, in some preliminary studies it was shown that even intramolecular aromatic substitutions are
Formation of Bicyclic Pyrroles and Furans Through an Enone Allene Photocycloaddition and Fragmentation Sequence
作者:Ginger Lutteke、Rana AlHussainy、Pauli J. Wrigstedt、B. T. B. Hue、René de Gelder、Jan H. van Maarseveen、Henk Hiemstra
DOI:10.1002/ejoc.200701017
日期:2008.2
acetonitrile at 300 nm resulted in the clean conversion of the starting materials into a mixture of photoproducts. The major product in all cases was a bicyclic pyrrole or furan fused to an eight membered ring (43–70 % yield). The formation of these products is thought to be a result of a heteroatom-induced fragmentation of the straight adduct (7). This is supported by irradiation of the carbon analogue
Enone radicals, generated from the corresponding iodo enones, or vinylogous esters and amides, undergo intramolecular cyclization to the tethered trimethylsilyl acetylenic side chain to give the carbo- or heterobicyclic enones.