Chiral N,N′-dioxide-Sc(NTf<sub>2</sub>)<sub>3</sub> complex-catalyzed asymmetric bromoamination of chalones with N-bromosuccinimide as both bromine and amide source
A chiral N,N[prime or minute]-dioxide-Sc(NTf2)3complex catalytic system has been developed to catalyze the asymmetric bromoamination reaction of chalones with N-bromosuccinimide.
Indium‐Catalysed Transfer Hydrogenation for the Reductive Cyclisation of 2‐Alkynyl Enones towards Trisubstituted Furans
作者:Luomo Li、Sascha Kail、Sebastian M. Weber、Gerhard Hilt
DOI:10.1002/anie.202109266
日期:2021.10.25
Indiumtribromidecatalysed the transferhydrogenation from dihydroaromatic compounds, such as the commercially available γ-terpinene, to enones, which resulted in the cyclisation to trisubstituted furan derivatives. The reaction was initiated by a Michael addition of a hydride nucleophile to the enone subunit followed by a Lewis-acid-assisted cyclisation and the formation of a furan–indium intermediate
三溴化铟催化从二氢芳香族化合物(例如市售的γ-萜品烯)到烯酮的转移氢化,从而环化为三取代的呋喃衍生物。该反应是通过将氢化物亲核试剂迈克尔加成到烯酮亚基上引发的,然后进行路易斯酸辅助环化并形成呋喃-铟中间体和衍生自二氢芳族起始材料的Wheland中间体。该产物是通过 Wheland 配合物质子化形成的,并取代了三溴化铟取代基。此外,二氢芳香族 HD 替代物的位点特异性氘标记导致了产物的位点特异性标记,并通过 H-D 加扰提供了对反应机制的有用见解。
Visible Light Photoredox Catalyzed Cascade Cyclizations of α-Bromochalcones or α-Bromocinnamates with Heteroarenes
作者:Suva Paria、Oliver Reiser
DOI:10.1002/adsc.201301069
日期:2014.2.10
AbstractVinyl radicals were generated from α‐bromochalcones or α‐bromocinnamate ethyl ester under visible light photoredox catalyzed conditions via an oxidative quenching cycle of the iridium complex [IrdF(CF3)ppy}2(dtbbpy)]PF6 and subjected to cascade cyclizations with heteroarenes entailing two consecutive CC bond formations and three CH activations. The process is amenable to furans, benzofurans, pyrroles, and indoles, giving rise to a broad variety of novel polycyclic frameworks in high yields under mild and environmentally benign reaction conditions.magnified image