1334591-54-6Relevant academic research and scientific papers
Iron-catalysed enantioselective Suzuki-Miyaura coupling of racemic alkyl bromides
Iwamoto, Takahiro,Okuzono, Chiemi,Adak, Laksmikanta,Jin, Masayoshi,Nakamura, Masaharu
, p. 1128 - 1131 (2019/01/28)
The first iron-catalysed enantioselective Suzuki-Miyaura coupling reaction has been developed. In the presence of catalytic amounts of FeCl2 and (R,R)-QuinoxP?, lithium arylborates are cross-coupled with tert-butyl α-bromopropionate in an enantioconvergent manner, enabling facile access to various optically active α-arylpropionic acids including several nonsteroidal anti-inflammatory drugs (NSAIDs) of commercial importance. (R,R)-QuinoxP? is specifically able to induce chirality when compared to analogous P-chiral ligands that give racemic products, highlighting the critical importance of transmetalation in the present asymmetric cross-coupling system.
CHIRAL PHOSPHINES FOR PALLADIUM-CATALYZED ASYMMETRIC ALPHA-ARYLATION OF ESTER ENOLATES TO PRODUCE TERTIARY STEREOCENTERS IN HIGH ENANTIOSELECTIVITY
-
Paragraph 00219-00220, (2013/03/26)
The disclosure provides new and improved methods for the Pd-catalyzed asymmetric α-arylation of ester compounds, which produce the corresponding α-aryl moiety in high enantioselectivity (generally >90% ee). The present methods utilize a palladium catalyst supported by new (R)-H8-BINOL-derived monophosphine ligands. The method is applicable to a wide variety of aryl triflate substrates having variations in both electronic and steric properties. These aryl triflate substrates react with various α-alkyl (Z)- and/or (E)-0-trimethylsilyl ketene acetals in the presence of a Pd catalyst, (R)-H8-BINOL-derived monophosphine ligand, and a mild activator, for example, LiOAC, to provide the asymmetric α-arylation of ester compounds in high ee.
An enantioselective, intermolecular α-arylation of ester enolates to form tertiary stereocenters
Huang, Zhiyan,Liu, Zheng,Zhou, Jianrong
supporting information; experimental part, p. 15882 - 15885 (2011/11/13)
In transition-metal catalyzed, asymmetric α-arylation of carbonyl compounds, formation of tertiary centers with high enantioselectivity is a longstanding problem, due to easy enolization of the monoarylation products. Herein, we report such examples using a palladium catalyst supported by a new, (R)-H8-BINOL-derived monophosphine. Silyl ketene acetals, together with a weakly basic activator, were used as equivalents of ester anions, and they reacted smoothly with aryl triflates in excellent enantiomeric excess (ee). The usefulness of the reaction was demonstrated in a gram-scale synthesis of (S)-Naproxen in 92% ee.
