Tandem Hydroalumination/Cu-Catalyzed Asymmetric Vinyl Metalation as a New Access to Enantioenriched Vinylcyclopropane Derivatives
作者:Daniel S. Müller、Veronika Werner、Sema Akyol、Hans-Günther Schmalz、Ilan Marek
DOI:10.1021/acs.orglett.7b01661
日期:2017.8.4
Herein, we report the first enantio- and diastereoselective addition of stereodefined vinyl organometallicreagents to cyclopropenes. The operationally simple tandem hydroalumination and copper-catalyzed vinylmetalation allows for the unique access of a diverse set of enantioenriched vinylcyclopropane derivatives.
An umpolung strategy has been developed for the synthesis of β,γ-unsaturatedketones utilizing nucleophilic β-alkenylation of N-alkoxyenamines, which are prepared in situ fromketones and isoxazolidine, with alkenyl aluminum reagents. Various β,γ-unsaturatedketones have been prepared following this simple procedure under mild conditions.
OLEFINATION OF KETONES USING 1,1-DIMETALLOALKANES DERIVED FROM<i>i</i>-Bu<sub>2</sub>AlCH=CHR - Cl<sub>2</sub>TiCp<sub>2</sub>SYSTEM
作者:Tadao Yoshida
DOI:10.1246/cl.1982.429
日期:1982.4.5
The alkylidenation of ketone carbonyls using 1,1-dimetalloalkanes prepared by the reaction of 1-alkenyldiisobutylalanes with titanocene dichloride afforded the corresponding olefins in good yields.
Palladium-catalyzed carbonylative synthesis of α,β-unsaturated amides from aryl azides and alkenylaluminum reagent
作者:Bo Chen、Xiao-Feng Wu
DOI:10.1016/j.jcat.2020.01.017
日期:2020.3
In this work, an interesting procedure for the synthesis of α,β-unsaturatedamides from aryl azides and alkenylaluminum reagent has been developed. With palladium as the catalyst and XPhos as the ligand under carbon monoxide pressure, the desired α,β-unsaturatedamides were isolated in good to excellent yields with good functional group tolerance. Remarkably, this procedure also represents an example
Protecting group controlled diastereoselective reduction of diprotected α,α-bis(hydroxymethyl)ketones derived from THYM*, using the DIBALH / MgBr2 system
The reduction of diprotected α,α-bis(hydroxymethyl)ketones 5, derived from the novel chiral building blocks THYM* 1 and BHYMA* 2 has been realized with good to excellent stereoselectivity (from 85:15 to 97:3), through a appropriate choice of the two protectinggroups and by employing the combination of DIBALH and MgBr2·Et2O.
新型手性结构单元THYM * 1和BHYMA * 2衍生的双保护α,α-双(羟甲基)酮5的还原反应具有良好的立体选择性(从85:15至97:3)。通过采用DIBALH和MgBr的组合两个保护基团和适当的选择2 ·的Et 2 O.