Synthesis of an Optically Active Platinum(II) Complex Containing a New Terdentate P-C-P Ligand and Its Catalytic Activity in the Asymmetric Aldol Reaction of Methyl Isocyanoacetate. X-ray Crystal Structure of [2,6-Bis[(1'S,2'S)-1'-(diphenylphosphino)-2',3'-O-isopropylidene-2',3'-dihydroxypropyl]phenyl](.eta.1-nitrato)platinum(II)

1994 ◽  
Vol 13 (5) ◽  
pp. 1607-1616 ◽  
Author(s):  
Fabrizio Gorla ◽  
Antonio Togni ◽  
Luigi M. Venanzi ◽  
Alberto Albinati ◽  
Francesca Lianza
Keyword(s):  
Crystal Structure ◽  
Catalytic Activity ◽  
Aldol Reaction ◽  
Optically Active ◽  
Asymmetric Aldol ◽  
X Ray ◽  
Asymmetric Aldol Reaction

Chiral Silver Alkoxide Catalyzed Asymmetric Aldol Reaction of Alkenyl Esters with Isatins

Synlett ◽  
2021 ◽  
Author(s):  
Akira Yanagisawa ◽  
Aiko Kawada
Keyword(s):  
Aldol Reaction ◽  
Optically Active ◽  
Asymmetric Aldol ◽  
Asymmetric Aldol Reaction ◽  
High Yields

AbstractA catalytic enantioselective aldol reaction of alkenyl esters with isatins was achieved using a DM-BINAP·AgOTf complex as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol or 2,2,2-trifluoroethanol. Optically active 3-alkylated 3-hydroxy-2-oxindoles having up to 98% ee were diastereoselectively obtained in moderate to high yields not only from cyclic alkenyl esters but also from acyclic ones through the in situ generated chiral silver enolates.

Asymmetric Aldol Reaction of Alkenyl Esters with α-Ketoesters Catalyzed by Chiral Tin Alkoxides

Synlett ◽  
2021 ◽  
Author(s):  
Akira Yanagisawa ◽  
Chika Uchiyama ◽  
Kotaro Takagi
Keyword(s):  
Sodium Methoxide ◽  
Aldol Reaction ◽  
Optically Active ◽  
Asymmetric Aldol ◽  
Asymmetric Aldol Reaction ◽  
Tertiary Carbon ◽  
High Yields

A catalytic enantioselective aldol reaction of alkenyl esters with α-ketoesters was achieved using an (R)-BINOL-derived chiral tin dibromide possessing a 4-t-butylphenyl group at 3- and 3’-positions as the chiral precatalyst in the presence of sodium methoxide and methanol. Optically active aldol products possessing a chiral tertiary carbon with up to 92% ee were diastereoselectively obtained in moderate to high yields not only from cyclic alkenyl esters but also from acyclic ones under the influence of the in situ generated chiral tin methoxide.

Novel chiral proline-based organocatalysts with amide and thiourea–amine units for highly efficient asymmetric aldol reaction in saturated brine without additives

2019 ◽  
Vol 97 (5) ◽  
pp. 352-359
Author(s):  
En-Jie Xu ◽  
Yan Song ◽  
Zhong-Lin Wei ◽  
Rui Wang ◽  
Hai-Feng Duan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Aldol Reaction ◽  
Asymmetric Aldol ◽  
Highly Efficient ◽  
Asymmetric Aldol Reaction ◽  
Benzaldehyde Derivatives

A series of novel proline-based organocatalysts with amide and thiourea-amine units (7a–7f) were developed and evaluated in the asymmetric aldol reaction of 4-nitrobenzaldehyde with cyclohexanone. The organocatalyst (7c or 7d, 5 mol%) exhibited efficient catalytic activity to afford aldol products in high diastereoselectivity (up to >99:1), enantioselectivity (up to >99%), and yield (up to >96%) at 0 °C in saturated brine without adding an acid. Aldol products of benzaldehyde derivatives almost universally provide high diastereoselectivity and enantioselectivity.

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