Monophosphine compound, transition metal complex thereof and production method of optically active compound using the complex as asymmetric catalyst
申请人:Carreira M. Erick
公开号:US20050277772A1
公开(公告)日:2005-12-15
The present invention provides a compound represented by the formula (I):
wherein ring A is void or a benzene ring optionally having substituent(s), R
1
and R
2
are each independently a phenyl group optionally having substituent(s), a cyclohexyl group and the like, R
3
and R
4
are each independently a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group and the like, and X is a residue represented by —OR
5
or —NHR
6
wherein R
5
and R
6
are a lower alkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s) and the like, a asymmetric transition metal complex containing the compound as a ligand and a production method of optically active compound using the complex as an asymmetric catalyst.
The environment-friendly condensation of Meldrum's acid and aromatic, heteroaromatic and hindered aliphatic aldehydes is performed carrying out the reaction in water at 75°C for 2 h, avoiding the addition of any catalyst.
Sc(OTf)<sub>3</sub>-Catalyzed Conjugate Allylation of Alkylidene Meldrum’s Acids
作者:Aaron M. Dumas、Eric Fillion
DOI:10.1021/ol9003959
日期:2009.5.7
Alkylidene Meldrum’s acids are allylated in a conjugate fashion by allyltin nucleophiles under mild Sc(OTf)3-catalyzed conditions. The addition is functional group tolerant and reactions with nonracemic alkylidenes are highlydiastereoselective. Allylation of alkylidenes derived from α-ketoesters yield all-carbon quaternary stereocenters.
Stereoselective Sequential Spirocyclopropanation/Cloke–Wilson Rearrangement Reactions for Synthesis of <i>trans</i>-β,γ-Disubstituted γ-Butyrolactones Using Alkylidene Meldrum’s Acid and Benzyl Halides
spirocyclopropanation/Cloke-Wilson rearrangement reactions have been developed to synthesize γ-butyrolactones using alkylidene Meldrum's acids and benzyl halides. The DBU-promoted spirocyclopropanation was carried out efficiently at room temperature to generate trans-isomeric spirocyclopropyl Meldrum's acid, and the following stereospecific thermal decarboxylative Cloke-Wilson rearrangement afforded trans-γ-butyrolactones
Photochemistry of o-methyl-substituted aromatic ketone with 5-isobutylidene-1,3-dioxane-4-,6-dione derivatives
作者:Takashi Tsuno、Kunio Sugiyama
DOI:10.1016/s0040-4039(00)78871-x
日期:1992.5
of o-methylacetophenone or o-methylbenzophenone with 5-isobutylidene-1,3-dioxane-4,6-diones produced novel adducts, bonding between the β-carbon of the acylales and the o-methyl carbon of the aromaticketones.