Asymmetric Syntheses of 8-Oxabicyclo[3,2,1]octanes: A Cationic Cascade Cyclization
作者:Bin Li、Yu-Jun Zhao、Yin-Chang Lai、Teck-Peng Loh
DOI:10.1002/anie.201202699
日期:2012.8.6
High octane: A novel and practical syntheses of 8‐oxabicyclo[3.2.1]octanes using a cationic cascade cyclization reaction has been developed (see scheme; TIPS=triisopropylsilyl). The diastereomer of the cyclization product isolated depends upon whether the acetal or aldehyde substrate is used.
A Facile Method for the Synthesis of Highly Substituted Six-Membered Rings: Mukaiyama−Aldol−Prins Cascade Reaction
作者:Hao Li、Teck-Peng Loh
DOI:10.1021/ol100937r
日期:2010.6.18
A highly efficient cascade reaction has been developed using cheap commercially available or easily accessible starting materials. It has the ability to construct highly functionalized six-membered ring with three to four stereogenic centers in high yields.
Control of up to Five Stereocenters in a Cascade Reaction: Synthesis of Highly Functionalized Five-Membered Rings
作者:Hao Li、Teck-Peng Loh
DOI:10.1021/ja801488z
日期:2008.6.1
Mukaiyama-Aldol and Prins reactions have been identified as highly efficient methods in C-C bond formation since they were discovered several decades ago. Since both reactions gave the same common intermediate, oxocarbonium, we intend to combine the two reactions into a domino process, which means the formation of multiple C-C bonds and stereogenic centers in one pot without isolation of any intermediates
自从几十年前发现 Mukaiyama-Aldol 和 Prins 反应以来,它们就被认为是形成 CC 键的高效方法。由于这两个反应都产生了相同的中间体氧碳鎓,我们打算将这两个反应组合成一个多米诺骨牌过程,这意味着在一个锅中形成多个 CC 键和立体中心,而无需分离任何中间体。我们设想涉及用路易斯酸 (TiBr4) 处理的甲硅烷基烯醇醚和缩醛的 Mukaiyama-Aldol 反应的多米诺反应将产生氧鎓中间体,在分子内 Prins 环化中被烯烃官能团捕获后,将产生环戊基环系统。
Base-Mediated α-<i>gem</i>-Difluoroalkenylations of Aldehydes and Ketones
作者:Yu-Qing Ni、Dong-Jie Li、Yan Mei、Yan Jiang、Jun-Lei Zhang、Ke-Han He、Fei Pan
DOI:10.1021/acs.orglett.3c02845
日期:2023.9.15
silyl enol ethers, enabling the efficient synthesis of carbonyl-substituted gem-difluoroalkenes. The merit of this protocol is exhibited by its mild reaction conditions, broad substrate scope, and scalable preparation. Notably, this method demonstrates its applicability for late-stage functionalization of structurally complex molecules. Moreover, we illustrate that the resulting products can serve as