Synthesis of 1,3-Aminoalcohols and Spirocyclic Azetidines via Tandem Hydroxymethylation and Aminomethylation Reaction of β-Keto Phosphonates with <i>N</i>-Nosyl-<i>O</i>-(2-bromoethyl)hydroxylamine
作者:Binyu Wu、Hongbing Chen、Min Gao、Xiangnan Gong、Lin Hu
DOI:10.1021/acs.orglett.1c01091
日期:2021.6.4
α-aminomethylation reaction of aromatic cyclic β-keto phosphonates with N-nosyl-O-(2-bromoethyl)hydroxylamine in the presence of DBU base has been developed, affording a range of 1,3-aminoalcohols in good yields. The resultant products could be flexibly transformed into the spirocyclic and bispirocyclic azetidines via one step of Mitsunobu reaction. Mechanistic study revealed that hydroxylamine in situ generated
Carbocation catalysed ring closing aldehyde–olefin metathesis
作者:Shengjun Ni、Johan Franzén
DOI:10.1039/c8cc06734a
日期:——
4-Phenylphenyl-diphenylmethylium tetrafluoroborate catalyses a rare high yielding intramolecular aldehyde–olefin metathesis of enals under mild reaction conditions and low catalyst loading.
作者:Rui Wang、Yi Chen、Mao Shu、Wenwen Zhao、Maoling Tao、Chao Du、Xiaoya Fu、Ao Li、Zhihua Lin
DOI:10.1002/chem.201905199
日期:2020.2.11
Compared with the ripeness of olefin metathesis, exploration of the construction of carbon-carbon double bonds through the catalytic carbonyl-olefin metathesis reaction remains stagnant and has received scant attention. Herein, a highly efficient AuCl3 -catalyzed intramolecular ring-closing carbonyl-olefin metathesis reaction is described. This method features easily accessible starting materials,
Nickel-Catalyzed Stereoselective Alkenylation of Ketones Mediated by Hydrazine
作者:Shumei Xia、Dawei Cao、Huiying Zeng、Liang-Nian He、Chao-Jun Li
DOI:10.1021/jacsau.2c00320
日期:2022.8.22
The direct conversion of naturally abundant carbonyl compounds provides a powerful platform for the efficient synthesis of valuable chemicals. In particular, the conversion of ketones to alkenes is a commonly encountered chemical transformation, often achieved via the multistep Shapiro reaction with tosylhydrazone and over stoichiometric organolithium or Grignard reagent. Herein, we report an earth
Catalytic Asymmetric Inverse‐Electron‐Demand Diels–Alder Reactions of 2‐Pyrones with Indenes: Total Syntheses of Cephanolides A and B
作者:Yang Lu、Meng‐Meng Xu、Zhi‐Mao Zhang、Junliang Zhang、Quan Cai
DOI:10.1002/anie.202112223
日期:2021.12.13
Catalyticasymmetric all-carbon-based inverse-electron-demand Diels–Alderreactions of 2-pyrones with electronically unbiased indenes have been realized. This method enables the rapid and enantioselective construction of a wide range of hexahydrofluorenyl bridged-lactone scaffolds. Based on this method, asymmetric total syntheses of cephanolides A and B have been accomplished.