Catalytic Enantioselective [3 + 2] Cycloaddition of α-Keto Ester Enolates and Nitrile Oxides
作者:Samuel L. Bartlett、Yoshihiro Sohtome、Daisuke Hashizume、Peter S. White、Miki Sawamura、Jeffrey S. Johnson、Mikiko Sodeoka
DOI:10.1021/jacs.7b03782
日期:2017.6.28
An enantioselective [3 + 2] cycloaddition reaction between nitrileoxides and transiently generated enolates of α-keto esters has been developed. The catalyst system was found to be compatible with in situ nitrile oxide-generation conditions. A versatile array of nitrileoxides and α-keto esters could participate in the cycloaddition, providing novel 5-hydroxy-2-isoxazolines in high chemical yield
Nickel(II)‐Catalyzed Diastereo‐ and Enantioselective Michael/ Hemiacetalization Cascade Reaction of α‐Ketoesters with 2‐(2‐Nitrovinyl)phenols
作者:Long Chen、Wu‐Lin Yang、Jia‐Huan Shen、Wei‐Ping Deng
DOI:10.1002/adsc.201900753
日期:2019.10.8
A nickel(II)/diamine‐catalyzed diastereo‐ and enantioselective Michael/hemiacetalization cascade reaction of α‐ketoesters with 2‐(2‐nitrovinyl)phenols has been established, thus providing a range of structurally diverse polysubstituted chromanes in good yields and excellent stereoselectivities (up to 89% yield, >20:1 dr, >99% ee). Moreover, the gram‐scale experiment was performed with only 0.5 mol%
作者:Blane P. Zavesky、Samuel L. Bartlett、Jeffrey S. Johnson
DOI:10.1021/acs.orglett.7b00761
日期:2017.4.21
PtBu3 has been applied to the coupling of α-ketoester enolates and aryl bromides. The reaction provides access to an array of β-stereogenic α-ketoesters. When the air-stable ligand precursor PtBu3·HBF4 is employed, the reaction can be carried out without use of a glovebox. The derived products are of broad interest given the prevalence of the α-ketoacid substructure in biologically important molecules
衍生自可商购的Pd 2(dba)3和P t Bu 3的催化剂体系已用于α-酮酸酯烯酸酯和芳基溴化物的偶联。该反应提供了进入一系列β-立体异构α-酮酯的途径。当使用空气稳定的配体前体P t Bu 3 ·HBF 4时,可以在不使用手套箱的情况下进行反应。鉴于生物学重要分子中α-酮酸亚结构的普遍性,衍生产品引起了广泛的兴趣。
A di‐
<i>tert</i>
‐butyl acrylate monomer for controlled radical photopolymerization
作者:Zachariah A. Page、Raghida Bou Zerdan、Will R. Gutekunst、Athina Anastasaki、Sungbaek Seo、Alaina J. McGrath、David J. Lunn、Paul G. Clark、Craig J. Hawker
DOI:10.1002/pola.28443
日期:2017.3
(diTBA) monomer for controlled radical polymerization is reported. This monomer complements the classical use of tert‐butyl acrylate (TBA) for synthesis of poly(acrylic acid) by increasing the density of carboxylic acids per repeat unit, while also increasing the flexibility of the carboxylic acid side‐chains. The monomer is well behaved under Cu(II)‐mediated photoinduced controlled radical polymerization
A biomimetic enantioselective transamination of α-keto ester derivatives can be realized under mild conditions by using chiral quaternary ammonium arenecarboxylates in the absence of base additives. The corresponding α-aminoacids can be used as versatile intermediates for further synthetic transformations that furnish chiral pyrrolidine and octahydroindolizine derivatives.