Enantioselective γ-Addition-Driven Cascade of β,γ-Unsaturated Ketones by Ion-Pair Catalysis: Access to Chiral 1,3-Dioxolochroman Scaffolds
作者:Xuemei Wang、Liang Zhou、Hongkui Zhang、Xiaoyu Ren、Guowei Gao、Tianli Wang
DOI:10.1021/acs.orglett.1c03567
日期:2022.1.14
A highlyenantioselective γ-addition-driven cascade of β,γ-unsaturated carbonyl compounds by bifunctional ion-pair catalysis has been developed. With this protocol, a range of functionalized chiral 1,3-dioxolochroman derivatives were prepared in high yields with superior stereoselectivities (>99% ee and >20:1 dr). The utility of this method was demonstrated by one-pot synthesis, scaled-up preparation
Highly Regio‐, Diastereo‐, and Enantioselective Synthesis of Tetrahydroazepines and Benzo[
<i>b</i>
]oxepines through Palladium‐Catalyzed [4+3] Cycloaddition Reactions
作者:Barry M. Trost、Zhijun Zuo
DOI:10.1002/anie.201911537
日期:2020.1.13
A novel Pd0 -catalyzed asymmetric [4+3] annulation reaction of two readily accessible starting materials has been developed for building seven-membered heterocyclic architectures. The potential [3+2] side pathway could be suppressed though fine tuning of the conditions. A broad scope of cycloaddition donors and acceptors participated in the transformation with excellent chemo-, regio-, diastereo-,
ortho-Quinone methides are useful transient synthetic intermediates in organic synthesis. These species are most often generated in situ by the acid- or base-mediated transformation of phenols that have been pre-functionalized at a benzylic position, or by biomimetic oxidation of the corresponding ortho-alkylphenols with metal oxidants or transition-metal complexes. Here we describe a method for the
Highly Stereoselective Construction of β,β-Diaryl-α-Branched Ketones by the Chiral Primary Amine-Catalyzed Asymmetric Retro-Claisen Reaction
作者:Yanfang Han、Long Zhang、Sanzhong Luo
DOI:10.1021/acs.orglett.2c00435
日期:2022.3.4
Highlydiastereo- and enantioselective retro-Claisen reaction of β-diketones with o-quinone methides has been developed by chiral primary amine catalysis. This reaction allows for efficient synthesis of chiral β,β-diaryl-α-branched ketones in moderate to good yields with excellent stereoselectivities. The reaction occurs via a tandem sequence of benzylic C–C bond formation, C–C bond cleavage, and stereospecific