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.
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
Single Electron Transfer in Michael Induced Ring Closure reactions
作者:H.M. Walborsky、M. Topolski
DOI:10.1016/s0040-4039(00)61538-1
日期:1993.11
Substituted cyclopropylether 3 is readily available from γ-bromoalkylidene malonate 2 via a Michael Induced Ring Closure (MIRC) reaction with sodium methoxide. SingleElectronTransfer mechanism is suggested for the key cyclization step to account for the observed high reactivity of a tertiary halide, phosphonium salt and nitro compound.
作者:Thomas F. Knöpfel、Pablo Zarotti、Takashi Ichikawa、Erick M. Carreira
DOI:10.1021/ja052411r
日期:2005.7.13
We document a copper-catalyzed, enantioselective, conjugateaddition involving the direct use of a terminal acetylene, which undergoes in situ metalation. The addition reactions of phenylacetylene to Meldrum's acid derived acceptors take place in aqueous media, without recourse to inert atmosphere. The success of the enantioselective process was enabled by the use of a new class of conveniently accessed
作者:Takumi Watanabe、Thomas F. Knöpfel、Erick M. Carreira
DOI:10.1021/ol035575q
日期:2003.11.1
[reaction: see text] The enantioselective conjugateadditionreaction of Et(2)Zn to Meldrum's acid derived acceptors, mediated by a catalyst formed from Cu(O(2)CCF(3))(2) and a phosphoramidite ligand, is reported. Adducts are obtained in useful yields and up to 94% ee.