Preparation of Quaternary Centers via Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling of Tertiary Sulfones
作者:Zachary T. Ariki、Yuuki Maekawa、Masakazu Nambo、Cathleen M. Crudden
DOI:10.1021/jacs.7b10855
日期:2018.1.10
benzylic and allylic sulfones with arylboroxines. A variety of tertiary sulfones, which can easily be prepared via a deprotonation-alkylation route, were reacted to afford symmetric and unsymmetric quaternary products in good yields. We highlight the use of either BrettPhos or Doyle's phosphines as effective ligands for these challenging desulfonative coupling reactions. The utility of this methodology
我们描述了叔苄基和烯丙基砜与芳基环硼烷的镍催化 Suzuki-Miyaura 交叉偶联的开发。可以通过去质子化-烷基化路线轻松制备的各种叔砜反应以良好的收率提供对称和不对称季产物。我们强调使用 BrettPhos 或 Doyle 膦作为这些具有挑战性的脱磺化偶联反应的有效配体。这种方法的实用性在维生素 D 受体调节剂类似物的简明合成中得到了证明。
Synthesis of β-acetoxy alcohols by PhI(OAc)<sub>2</sub>-mediated metal-free diastereoselective β-acetoxylation of alcohols
作者:Chun-Yang Zhao、Liang-Gui Li、Qing-Rong Liu、Cheng-Xue Pan、Gui-Fa Su、Dong-Liang Mo
DOI:10.1039/c6ob01203e
日期:——
β-Acetoxy alcohols can be synthesized in good yields with excellent diastereoselectivity from tertiary alcohols through PhI(OAc)2-mediated metal-free β-acetoxylation. Mechanistic studies showed that the β-acetoxylation process might undergo dehydration and sequential highly regioselective and diastereoseletive dioxygenation. Gram scale and diverse useful scaffolds could be prepared via this β-acetoxylation
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‐Heterocyclic‐Carbene‐Coordinated Palladium Catalysts for 1,2‐Addition of Arylboron Compounds to Carbonyl Compounds
作者:Yuta Okuda、Masahiro Nagaoka、Tetsuya Yamamoto
DOI:10.1002/cctc.202001464
日期:2020.12.16
primary, secondary, and tertiary alcohols by the 1,2‐addition of arylboronic acids or boronates to carbonyl compounds, including unactivated ketones, using novel bulky yet flexible N‐heterocyclic carbene (NHC)‐coordinated 2,6‐di(pentan‐3‐yl)aniline (IPent)‐based cyclometallated palladium complexes (CYPs) as catalysts is reported. The PhS‐IPent‐CYP‐catalyzed reactions are efficient at low catalyst loadings
Halogenation of 1,1-diarylethylenes by N-halosuccinimides
作者:Ge Zhang、Rui-Xue Bai、Chu-Han Li、Chen-Guo Feng、Guo-Qiang Lin
DOI:10.1016/j.tet.2018.11.018
日期:2019.3
An efficient method for the preparation of 2,2-diarylvinyl halides from the corresponding 1,1-diarylethylenes has been developed. N-Halosuccinimides (N-bromosuccinimide or N-chlorosuccinimide) were used as the halogenation reagents. The practicability of this method is highlighted by its simple operation, broad substrate scope and capability for large-scale reaction.