Very short highly enantioselective Grignard synthesis of 2,2-disubstituted tetrahydrofurans and tetrahydropyrans
作者:Claudio Monasterolo、Helge Müller-Bunz、Declan G. Gilheany
DOI:10.1039/c9sc00978g
日期:——
synthesis of tertiary alcohols. In turn this enables the simple, short and highly enantioselective (up to 96% ee) preparation of chiral 2,2-disubstituted THFs and THPs. Thus, asymmetric addition of Grignard reagents to γ-chlorobutyrophenones and δ-chlorovalerophenones takes place in the presence of a chiral diaminocyclohexyl-derived tridentate ligand and subsequent base-promoted intramolecular cyclisation
Harnessing the Power of the Asymmetric Grignard Synthesis of Tertiary Alcohols: Ligand Development and Improved Scope Exemplified by One-Step Gossonorol Synthesis
作者:Saranna E. Kavanagh、Declan G. Gilheany
DOI:10.1021/acs.orglett.0c02629
日期:2020.11.6
A series of N-substituted cyclohexyldiaminophenolic ligands for the asymmetric Grignard synthesis of tertiary alcohols is reported. The 2,5-dimethylpyrrole-decorated ligand led to improved enantioselectivities and broadened the scope of the methodology. As an exemplar, we report an unprecedented highly selective one-step synthesis of gossonorol in 93% ee, also constituting the shortest formal syntheses
作者:Rajat Maji、Santanu Ghosh、Oleg Grossmann、Pinglu Zhang、Markus Leutzsch、Nobuya Tsuji、Benjamin List
DOI:10.1021/jacs.3c01404
日期:2023.4.26
Despite recent advancements in the development of catalyticasymmetric electrophile induced lactonization reactions of olefinic carboxylic acids, the archetypical hydrolactonization has long remained an unsolved and well-recognized challenge. Here, we report the realization of a catalyticasymmetric hydrolactonization using a confined imidodiphosphorimidate (IDPi) Brønsted acid catalyst. The method
尽管最近在催化不对称亲电试剂诱导的烯烃羧酸内酯化反应的发展方面取得了进展,但原型加氢内酯化长期以来一直是一个未解决且公认的挑战。在这里,我们报告了使用限制性亚氨基二磷酸酯 (IDPi) 布朗斯台德酸催化剂实现催化不对称加氢内酯化。该方法操作简单、可扩展且与多种底物兼容。它的潜力通过倍半萜烯 (−)-boivinianin A 和 (+)-gossonorol 的简明合成得到展示。通过深入的物理化学和 DFT 分析,我们得出了该反应的机理和对映选择性的细微差别。
Enantioselective synthesis of (+)-gossonorol and related systems using organozinc reagents
作者:Susana González-López、Miguel Yus、Diego J. Ramón
DOI:10.1016/j.tetasy.2012.04.003
日期:2012.4
The sesquiterpene (+)-gossonorol is prepared in only three synthetic steps in 60% overall yield and 82% ee from commercially available reagents. The key asymmetric step is the catalytic enantioselective addition of dimethylzinc to 5-methyl-1-(2-methylphenyl)hex-4-en-1-one catalyzed by chiral isoborneolsulfonamide ligands in the presence of titanium tetraisopropoxide. The modular approach allows the synthesis not only of the aforementioned natural product but also other products arising from the corresponding processes of ethylation, phenylation, and ethynylation, just by changing the final nucleophilic reagent and using the same isoborneol type ligand. (C) 2012 Elsevier Ltd. All rights reserved.