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.
Solvent-free Knoevenagel reaction catalysed by reusable pyrrolidinium base protic ionic liquids (PyrrILs): synthesis of long-chain alkylidenes
作者:R. C. M. Alves Sobrinho、P. M. de Oliveira、C. R. Montes D'Oca、D. Russowsky、M. G. Montes D'Oca
DOI:10.1039/c6ra25595g
日期:——
pyrrolidinium ionicliquid (PyrrIL) catalysis system was developed and used in a Knoevenagelcondensation reaction of long-chain aldehydes with several 1,3-dicarbonyl compounds. The Knoevenagelcondensation promoted by the PyrrILs proceeded smoothly and cleanly in solvent-free conditions, yielding good quantities of the condensation products, long-chain alkylidenes. Moreover, this catalysis system was recyclable
Boron/zinc exchange for the conjugate arylation of unsaturated Meldrum’s acid derivatives
作者:Micaela Jardim、Lucas L. Baldassari、Maria Eduarda Contreira、Angélica V. Moro、Diogo S. Lüdtke
DOI:10.1016/j.tet.2020.130967
日期:2020.12
approach for the conjugate arylation reaction of unsaturated Meldrum’s acid derivatives is reported. The reaction takes place through a Boron-Zinc exchange reaction between arylboronic acids and diethylzinc and the subsequent transfer of thus generated reactive aryl groups to the β-position of the double bond of the Meldrum’s derivatives. The compounds obtained are valuable synthetic intermediates and
Transient [3,3] Cope rearrangement of 3,3-dicyano-1,5-dienes: computational analysis and 2-step synthesis of arylcycloheptanes
作者:Ehsan Fereyduni、Jacob N. Sanders、Gabriel Gonzalez、K. N. Houk、Alexander J. Grenning
DOI:10.1039/c8sc03057j
日期:——
reported. The two-step route from Knoevenagel adducts and allylic electrophiles is made possible through the design of a Coperearrangement that utilizes a “traceless” activating group to promote an otherwise thermodynamically unfavorable transformation. Experimentally, the [3,3] rearrangement occurrs transiently at room temperature with a computed barrier of 19.5 kcal mol−1, which ultimately allows for three-component
A Simple Organocatalytic Enantioselective Synthesis of Pregabalin
作者:Oriol Bassas、Juhani Huuskonen、Kari Rissanen、Ari M. P. Koskinen
DOI:10.1002/ejoc.200801220
日期:2009.3
synthetic sequence is the Michaeladdition reaction of Meldrum's acid to a nitroalkene mediated by a quinidine derived thiourea. A variety of novel catalysts bearing different groups at the thiourea moiety were synthesized and tested. The most successful catalyst that incorporates a trityl substituent provided up to 75 % ee of (S)-4. The conjugate addition reaction was carried out on a multigram scale