Article
Biochemistry & Molecular Biology
Mary C. C. Hennessy, Hirenkumar Gandhi, Timothy P. P. O'Sullivan
Summary: A methodology for synthesizing γ, δ-unsaturated β-keto esters through asymmetric peroxidation is described. The cinchona-derived organocatalyst allows for high enantioselectivity (up to 95:5) in obtaining the desired γ-peroxy-β-keto esters. Furthermore, the resulting δ-peroxy esters can be easily reduced to chiral δ-hydroxy-β-keto esters without affecting the functionality of the β-keto ester. Importantly, this chemistry provides a concise route to chiral 1,2-dioxolanes, a common motif in bioactive natural products, via a novel P2O5-mediated cyclization of the corresponding δ-peroxy-β-hydroxy esters.
Article
Biochemistry & Molecular Biology
S. Ferron, P. Jehan, X. Guillory, P. Uriac
Summary: The reactivity of purified depsides obtained from European lichens was investigated. These depsides can lead to the formation of fluorescent compounds in the presence of KOH solution. A mechanistic explanation was proposed and a chemical probe useful for lichen determination was designed.
Review
Multidisciplinary Sciences
Ruixian Deng, Tian-Jiao Han, Xiang Gao, Yuan-Fu Yang, Guang-Jian Mei
Summary: beta,gamma-Unsaturated alpha-ketoesters are versatile organic synthons in catalytic asymmetric transformations. The highly efficient creation of stereogenic centers with excellent enantioselectivity is achieved through the bidentate coordination of their unique 1,2-dicarbonyl motif to chiral messengers. Various reaction modes of beta,gamma-Unsaturated alpha-ketoesters involving multiple reaction sites have been developed in the past five years. This review provides an updated overview for chemists working in this field, facilitating their discoveries in asymmetric catalysis, natural products synthesis, and drug development.
Article
Chemistry, Organic
Zhi-Wei Ma, Chuan-Chuan Wang, Xiao-Pei Chen, Ai-Qin Li, Jing-Chao Tao, Quan-Jian Lv
Summary: A new organocatalyst system has been developed for the asymmetric Michael addition of cyclic diketones to beta,gamma-unsaturated alpha-keto esters. The system showed high efficiency with low catalyst loading and mild reaction conditions, resulting in the synthesis of chiral bicyclic compounds with high yields and excellent enantioselectivities.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Organic
Meng-Cheng Zhang, Dong-Chao Wang, Gui-Rong Qu, Hai-Ming Guo
Summary: The first catalytic asymmetric route to synthesize chiral thiohydantoins containing a quaternary stereogenic center has been established using a chiral phosphoric acid catalyst, achieving high yields and excellent enantioselectivities. This reaction also allows for the construction of two C-N bonds.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Wenjing Lu, Jindong Li, Yangmian Lu, Zhenggen Zha, Zhiyong Wang
Summary: An enantioselective Mukaiyama 1,2 addition of silyl enol ethers with oxindolyl beta,gamma-unsaturated alpha-keto esters was developed using a chiral L-Cu complex as catalyst. The reaction proceeded rapidly under mild conditions, providing a series of chiral beta-hydroxyl carbonyl compounds with oxindolyl backbone skeleton in high yields and excellent enantioselectivities, up to 99%, as well as moderate to high diastereoselectivities, up to >20 : 1. This method offered an elegant synthesis route for these compounds.
Article
Chemistry, Organic
Ya Xiong, Xiao-Xue Han, Yu Lu, Hui-Juan Wang, Min Zhang, Xiong-Wei Liu
Summary: Inspired by fluorine-containing molecules and pyrrolidinyl spirooxindoles, a highly diastereoselective [3 + 2] cycloaddition reaction was reported for incorporating CF3 groups into pharmaceutically important compounds. The reaction, catalyzed by DABCO, achieved high efficiency with up to 93% yield and >20:1 diastereomeric ratio. The use of beta,gamma-unsaturated alpha-keto esters as substrates expanded the scope of applicability.
