An efficient RhII -catalyzed synthesis of functionalized α-vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C-C bond cleavage of the cyclopropane intermediates leads to formation of α-vinyl aldehyde derivatives
Asymmetric Copper-Catalyzed Carbozincation of Cyclopropenes en Route to the Formation of Diastereo- and Enantiomerically Enriched Polysubstituted Cyclopropanes
作者:Daniel S. Müller、Ilan Marek
DOI:10.1021/jacs.5b11220
日期:2015.12.16
The enantioselective synthesis of cyclopropylzinc reagents has been achieved via a copper-catalyzed carbozincation of 3,3-disubstituted cyclopropenes with diorganozincreagents. The obtained organozinc compounds can be easily functionalized with a broad range of electrophiles, including palladium-catalyzed cross-couplings, affording highly substituted cyclopropanes. The operationally simple procedure
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.
Copper‐Catalyzed Enantio‐ and Diastereoselective Addition of Silicon Nucleophiles to 3,3‐Disubstituted Cyclopropenes
作者:Liangliang Zhang、Martin Oestreich
DOI:10.1002/chem.201904272
日期:2019.11.13
A highly stereocontrolled syn-addition of silicon nucleophiles across cyclopropenes with two different geminal substituents at C3 is reported. Diastereomeric ratios are excellent throughout (d.r.≥98:2) and enantiomeric excesses usually higher than 90 %, even reaching 99 %. This copper-catalyzed C-Si bond formation closes the gap of the direct synthesis of α-chiral cyclopropylsilanes.
Gold(<scp>i</scp>)-catalysed synthesis of conjugated trienes
作者:Maximillian S. Hadfield、Ai-Lan Lee
DOI:10.1039/c0cc04217j
日期:——
Gold(I)-catalysed reaction between cyclopropenes and furans produces functionalised conjugated trienes. The reaction is mild, facile and proceeds with very low catalyst loadings.