Showing papers on "Chiral Lewis acid published in 2018"
TL;DR: The synthetic potential of this method was illustrated by conversion of the product to various cyclic compounds such as γ-lactone, cyclobutanol, and cyclopentanone.
Abstract: Chiral Lewis acid catalyzed asymmetric formation of cyclobutanones from α-silyloxyacroleins and α-alkyl or α-aryl diazoesters has been developed. In the presence of a chiral oxazaborolidinium ion catalyst, various α-silyloxycyclobutanones possessing a chiral β-quaternary center were synthesized in high yield (up to 91%) with excellent enantio- and diastereoselectivity (up to 98% ee and up to >20:1 dr) through tandem cyclopropanation/semipinacol rearrangement. The synthetic potential of this method was illustrated by conversion of the product to various cyclic compounds such as γ-lactone, cyclobutanol, and cyclopentanone.
56 citations
TL;DR: In this article, the synthesis and design of octahedral stereogenic-at-metal complexes featuring chiral ligands and their application as chiral catalysts in various asymmetric reactions are highlighted and discussed.
42 citations
28 citations
TL;DR: An unexpected homologation/dyotropic rearrangement/interconversion/[3+2] cycloaddition cascade reaction of α-diazoester-terminated N-propyl-substituted isatin derivatives was achieved in the presence of a chiral N,N'-dioxide/ScIII catalyst.
Abstract: An unexpected homologation/dyotropic rearrangement/interconversion/[3+2] cycloaddition cascade reaction of α-diazoester-terminated N-propyl-substituted isatin derivatives was achieved in the presence of a chiral N,N'-dioxide/ScIII catalyst. This catalytic manifold allows rapid construction of several classes of dimeric polycyclic compounds with good yields and high levels of diastereo- and enantioselectivity (up to 99 % ee). Furthermore, macrocyclic dimers can be obtained by an intermolecular homologation process.
20 citations
TL;DR: Enantioselective cyclopropanation and C-H insertion reactions of α-substituted vinyl ketones with α-diazoesters have been accomplished using a N,N'-dioxide-scandium(iii) complex catalyst.
15 citations
TL;DR: In this article, a variety of nucleophilic and Lewis acid catalysts were examined for use in promoting the synthesis of organophosphate triesters, including MgSO4.
5 citations
Patent•
09 Jan 2018
TL;DR: In this article, an asymmetric synthesis method for synthesizing 1-aryl-1H-pyridine[3,4-4]indole-3-carboxylic acid methyl ester derivatives containing two chiral centers from (R)methyl-2-amino-3-( 1H-indol-3yl)propanoate and aldehyde as main starting materials under catalysis of a catalyst, namely, chiral Lewis acid formed by a chiral tridentate ligand compound L and Ti(O-iPr)4.
Abstract: The invention discloses an asymmetric synthesis method for synthesizing 1-aryl-1H-pyridine[3,4-4]indole-3-carboxylic acid methyl ester derivatives containing two chiral centers from (R)methyl-2-amino-3-(1H-indol-3-yl)propanoate and aldehyde as main starting materials under catalysis of a catalyst, namely, chiral Lewis acid formed by a chiral tridentate ligand compound L and Ti(O-iPr)4. Compared with the prior art, the method has the advantages that the reaction yield is increased and the reaction non-correspondence selectivity is remarkably improved.
1 citations
TL;DR: In this article, the authors present an approach approaching sub-ppm-level asymmetric organocatalysis of a highly Challenging and Scalable Carbon-Carbon Bond Forming Reaction.
Abstract: 1089 H . Y . B A E, D . H Ö F L E R , P . S . J . K AI B , P . K A SA P L A R , C . K . D E , A . DÖ H R I N G , S . L E E, K . K A U P M E E S, I . L E I T O , B . L I ST * ( M A X P L AN C K I N S T I T U T F ÜR K O H L E N FO R S C H U N G , M ÜL HE I M A N D E R R UH R, G E R M A N Y A N D U N I V E R S I T Y OF TA R T U , E S T O N I A) Approaching Sub-ppm-Level Asymmetric Organocatalysis of a Highly Challenging and Scalable Carbon–Carbon Bond Forming Reaction Nat. Chem. 2018, 10, 888–894.