An Enantioselective, Intermolecular α-Arylation of Ester Enolates To Form Tertiary Stereocenters
作者:Zhiyan Huang、Zheng Liu、Jianrong (Steve) Zhou
DOI:10.1021/ja2066829
日期:2011.10.12
asymmetric α-arylation of carbonylcompounds, 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)-H(8)-BINOL-derived monophosphine. Silyl ketene acetals, together with a weakly basic activator, were used as equivalents of ester anions
在过渡金属催化的羰基化合物的不对称α-芳基化中,由于单芳基化产物容易烯醇化,形成具有高对映选择性的三级中心是一个长期存在的问题。在此,我们报告了使用由新的 (R)-H(8)-BINOL 衍生的单膦支持的钯催化剂的示例。甲硅烷基乙烯酮缩醛与弱碱性活化剂一起用作酯阴离子的等价物,它们与芳基三氟甲磺酸酯以优异的对映体过量 (ee) 顺利反应。该反应的有效性在 92% ee 的 (S)-萘普生的克级合成中得到证明。
CHIRAL PHOSPHINES FOR PALLADIUM-CATALYZED ASYMMETRIC ALPHA-ARYLATION OF ESTER ENOLATES TO PRODUCE TERTIARY STEREOCENTERS IN HIGH ENANTIOSELECTIVITY
申请人:Zhou Steve Jianrong
公开号:US20150166586A1
公开(公告)日:2015-06-18
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)—H
8
-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)—H
8
-BINOL-derived monophosphine ligand, and a mild activator, for example, LiOAC, to provide the asymmetric α-arylation of ester compounds in high ee.
[EN] CHIRAL PHOSPHINES FOR PALLADIUM-CATALYZED ASYMMETRIC ALPHA-ARYLATION OF ESTER ENOLATES TO PRODUCE TERTIARY STEREOCENTERS IN HIGH ENANTIOSELECTIVITY<br/>[FR] PHOSPHINES CHIRALES POUR L'ALPHA-ARYLATION ASYMÉTRIQUE CATALYSÉE PAR LE PALLADIUM DES ÉNOLATES D'ESTER POUR OBTENIR DES STÉRÉOCENTRES TERTIAIRES À UNE ÉNANTIOSÉLECTIVITÉ ÉLEVÉE
申请人:UNIV NANYANG TECH
公开号:WO2013028132A9
公开(公告)日:2013-08-22
US9512155B2
申请人:——
公开号:US9512155B2
公开(公告)日:2016-12-06
Achieving Vinylic Selectivity in Mizoroki-Heck Reaction of Cyclic Olefins
作者:Xiaojin Wu、Yunpeng Lu、Hajime Hirao、Jianrong Steve Zhou
DOI:10.1002/chem.201204427
日期:2013.5.3
In Heck reactions of cyclicolefins, the products usually have aryl groups that end up at the allylic and/or homoallylic position. We herein report new selectivity that adds aryl groups to the vinylic position. Cyclicolefins of various ring size worked well. The desired isomers were produced by palladium–hydride‐catalyzed isomerization of the initial products. Thus, a specific catalyst must be used