Applications of Allylsamarium Bromide as a Grignard Reagent and a Single-Electron Transfer Reagent in the One-Pot Synthesis of Dienes and Trienes
作者:Yuanyuan Hu、Tao Zhao、Songlin Zhang
DOI:10.1002/chem.200901927
日期:2010.2.1
reagent and a single‐electron transfer (SET) reagent in the reaction of α‐halo, γ‐halo‐α,β‐unsaturated ketones and esters with allylsamarium bromide is reported for the first time in this paper. From a synthetic point of view, a general, efficient and experimentally simple one‐pot method for the preparation of 1,4‐dienes and trienes is developed. A possible mechanism of the transformation is proposed.
Formation of quaternary carbons through cobalt-catalyzed C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Negishi cross-coupling
作者:Eduardo Palao、Enol López、Iván Torres-Moya、Antonio de la Hoz、Ángel Díaz-Ortiz、Jesús Alcázar
DOI:10.1039/d0cc02734k
日期:——
quaternary carbons is a key challenge in organic and medicinal chemistry. We report a cobalt-catalyzed C(sp3)–C(sp3) cross-coupling that allows for the introduction of benzyl, heteroarylmethylzinc and allyl groups to halo-carbonyl substrates. The cross-coupling reaction is selective for C(sp3)-over C(sp2)-halides, in contrast to most used catalytic metals, and allows access to novel scaffolds of pharmaceutical
Directed Copper-Catalyzed Intermolecular Heck-Type Reaction of Unactivated Olefins and Alkyl Halides
作者:Chunlin Tang、Ran Zhang、Bo Zhu、Junkai Fu、Yi Deng、Li Tian、Wei Guan、Xihe Bi
DOI:10.1021/jacs.8b10874
日期:2018.12.12
A new type of intermolecular alkylative olefination of unactivated olefins and alkyl halides has been realized for the first time. This copper-promoted Heck-type reaction employs a directing-group strategy to efficiently produce the coupled alkyl olefin products with excellent regio- and stereoselectivity. A broad substrate scope including 1°, 2°, and 3° alkyl bromides and various nonactivated alkenes
up to 68%. Derivatives containing spiro systems in which carbon C-5 of the thiazole ring is the linker atom were obtained in the presence of N,N-diisopropylethylamine. Some of the obtained compounds, at a concentration of 10 μM have activity in the inhibition of 11β-HSD1 up to 71%. IC50 value for the most active compound: 2-(allylamino)-1-thia-3-azaspiro[4.5]dec-2-en-4-one is 2.5 µM. With a high degree
Cu-Catalysed oxidant-free cascade ester amidation/radical cyclization of 2-amino-1,4-napthoquinones with α-bromocarboxylates to afford benzo[f]indole-2,4,9(3H)-triones.