TRANS-3,5-DISUBSTITUTEDPYRROLIDINE: ORGANOCATALYST FOR anti-MANNICH REACTIONS
申请人:Tanaka Fujie
公开号:US20070117986A1
公开(公告)日:2007-05-24
A compound of Formula I is disclosed, in which R is a substituent containing a hydrogen bond-forming atom within three atoms from the ring carbon to which the substituent is bonded; X is CH
2
, O, S or NR
1
, wherein R
1
is a hydrocarbyl group or an amino-protecting group having one to about 18 carbon atoms; R
2
is hydrido or a hydrocarbyl group containing one to about twelve carbon atoms; and R
3
is hydrido or methyl, but both R
2
and R
3
are not hydrido when X is CH
2
A molecule of Formula I and those in which R
2
and R
3
can both be hydrido (Formula X) functions as a catalyst in a Mannich reaction to asymmetrically form β-aminoaldehyde or β-aminoketone diastereomeric products having two chiral centers on adjacent carbon atoms and in which the anti-diastereomers are in excess over the syn-diastereomers. Methods for carrying out those syntheses are also disclosed.
A direct asymmetric Mannich reaction using a novel axiallychiralamino trifluoromethanesulfonamide (S)-3 has been developed in highly anti-selective and enantioselective manners. Thus, in the presence of a catalytic amount of (S)-3, the reactionsbetweenaldehydes and the alpha-imino ester 4 proceed smoothly to give the functional beta-amino aldehydes with significantly higher anti/syn ratio and enantioselectivity
Direct organocatalytic asymmetric Mannich-type reactions in aqueous media: one-pot Mannich-allylation reactions
作者:Armando Córdova、Carlos F Barbas
DOI:10.1016/s0040-4039(03)00019-4
日期:2003.2
organocatalytic asymmetric Mannich-type reactions in aqueousmedia are demonstrated herein. l-Proline-catalyzed reactions in aqueousmedia to provide β-formyl substituted α-amino acid derivatives with excellent diastereoselectivities (dr up to 19:1, syn/anti) and high enantioselectivities (ee between 72 and >99%). These conditions provided for the development of novel one-potasymmetric syntheses of cyclic
general efficient organocatalyst suitable for various types of anti-Mannichreactions and broad substrate scope. Excellent results (up to 98% yield, >99% ee and >99 : 1 dr) were achieved with 5 mol% catalyst load. Sulfones with ortho substituents or very strong withdrawing groups on the aromatic ring, which have been regarded as challenging substrates in the direct anti-Mannichreactions of aldehydes with
Highly Active Organocatalysts for Asymmetric anti-Mannich Reactions
作者:Rafael Martín-Rapún、Xinyuan Fan、Sonia Sayalero、Mahboubeh Bahramnejad、Félix Cuevas、Miquel A. Pericàs
DOI:10.1002/chem.201101513
日期:2011.8.1
of enantiopure 4‐oxy‐substituted 3‐aminopyrrolidines arising from the enantioselective ring‐opening of meso‐3‐pyrroline oxide have been developed as catalysts for the asymmetric, anti‐selective Mannichreaction (see scheme; PMP=p‐methoxyphenyl; PG=protecting group). Very high catalytic activity (down to 0.01 mol % loading) and stereoselectivity have been recorded.