One-Pot Synthesis of Homoallylic Ketones from the Addition of Vinyl Grignard Reagent to Carboxylic Esters
作者:Karl A. Hansford、James E. Dettwiler、William D. Lubell
DOI:10.1021/ol0359822
日期:2003.12.1
Fifteen homoallylic ketones have been synthesized in 26-77% yields on treatment of aromatic, aliphatic, and alpha-amino methyl carboxylates with excess vinylmagnesium bromide and catalytic amounts of a copper salt in THF. Alpha-amino homoallylic ketones derived from N-protected alpha-amino esters possessing aliphatic and alcohol side chains were synthesized in > or =98% enantiomeric purity. [reaction:
Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts
作者:Prakash Basnet、Shekhar KC、Roshan K. Dhungana、Bijay Shrestha、Timothy J. Boyle、Ramesh Giri
DOI:10.1021/jacs.8b09401
日期:2018.11.21
We disclose unprecedented synergistic bimetallic Ni/Ag and Ni/Cu catalysts for regioselective γ,δ-diarylation of unactivated alkenes in simple ketimines with aryl halides and arylzinc reagents. The bimetallic synergy, which generates cationic Ni(II) species during reaction, promotes migratory insertion and transmetalation steps and suppresses β-H elimination and cross-coupling, the major side reactions
Ni-Catalyzed Regioselective β,δ-Diarylation of Unactivated Olefins in Ketimines via Ligand-Enabled Contraction of Transient Nickellacycles: Rapid Access to Remotely Diarylated Ketones
作者:Prakash Basnet、Roshan K. Dhungana、Surendra Thapa、Bijay Shrestha、Shekhar KC、Jeremiah M. Sears、Ramesh Giri
DOI:10.1021/jacs.8b03163
日期:2018.6.27
zed regioselective β,δ-diarylation of unactivated olefins in ketimines with arylhalides and arylzinc reagents. This diarylation proceeds at remote locations to the carbonyl group to afford, after simple H+ workup, diversely substituted β,δ-diarylketones that are otherwise difficult to access readily with existing methods. Deuterium-labeling and crossover experiments indicate that diarylation proceeds
Three-step synthetic pathway to fused bicyclic hydantoins involving a selenocyclization step
作者:Biljana M. Šmit、Radoslav Z. Pavlović
DOI:10.1016/j.tet.2014.12.088
日期:2015.2
the synthesis of conformationally constrained fusedbicyclic scaffold. They are assembled by a three-step reaction sequence from two variable building blocks (readily available β-ketoesters and alkenyl halides) by combining a Bucherer–Bergs reaction with a final selenium-promoted intramolecular cyclization as a key step. The chemoselectivity of this bicyclic hydantoin formation is strongly influenced
Stereocontrolled concise synthesis of (±)-halosaline through intramolecular C-H amination
作者:Chun-Yan Meng、Xiao Liang、Hongbin Zhang、Kun Wei、Yu-Rong Yang
DOI:10.1016/j.tetlet.2019.05.068
日期:2019.7
Total synthesis of 2-(2-hydroxyalkyl)-piperidine alkaloid (±)-halosaline is described from 7-octen-4-ol using a Rh-catalyzed chemo- and diastereo-selective intramolecular CH amination of sulfamate ester, ring-closing metathesis, and SN2 displacement reaction of the six-membered ring sulfamidate as the key steps.
使用Rh催化的氨基磺酸氨基磺酸酯化学和非对映选择性分子内C H胺化反应,由7-辛烯-4-醇描述了2-(2-羟烷基)-哌啶生物碱(±)-卤代烷的全合成。复分解和六元环氨基磺酸盐的S N 2置换反应为关键步骤。