Nickel-Catalyzed Enantioselective α-Alkenylation of <i>N</i>-Sulfonyl Amines: Modular Access to Chiral α-Branched Amines
作者:Lun Li、Yu-Cheng Liu、Hang Shi
DOI:10.1021/jacs.1c00622
日期:2021.3.24
α-branched amines are common structural motifs in functional materials, pharmaceuticals, and chiral catalysts. Therefore, developing efficient methods for preparing compounds with these privileged scaffolds is an important endeavor in synthetic chemistry. Herein, we describe an atom-economical, modular method for a nickel-catalyzed enantioselective α-alkenylation of readily available linear N-sulfonyl amines
nitroarenes. The important features are the introduction of N-acetoxyacetamide as a new directing group, redox-neutral annulation, an additive-free approach, wide functional group tolerance, an intramolecular version, and a one-pot reaction of nitroarenes. The method was further extended to the synthesis of potent higher analogues of indole, viz., pyrrolo[3,2-f]indoles and dibenzo[a,c]carbazoles. In addition
N-乙酰氧基乙酰苯胺的一般和有效的铑催化氧化还原中性环化,容易从硝基芳烃中获得,与炔烃已经完成,用于合成取代的吲哚衍生物。从各种取代的N-乙酰氧基乙酰苯胺和对称/不对称炔烃中获得了范围广泛的取代 2,3-二芳基吲哚,产率从良好到优异。所开发的方法成功地与N-乙酰氧基乙酰苯胺的合成相结合,用于从硝基芳烃中有效地一锅法合成吲哚。重要的特点是引入了N-乙酰氧基乙酰胺作为新的导向基团,氧化还原中性环化,无添加剂方法,广泛的官能团耐受性,分子内形式和硝基芳烃的一锅反应。该方法进一步扩展到合成有效的高级吲哚类似物,即。、吡咯并[3,2- f ]吲哚和二苯并[ a , c ]咔唑。此外,基于潜在芳基-Rh中间体的分离和化学计量研究,提出了一种合理的机制。
Copper catalyzed/mediated direct B–H alkenylation/alkynylation in carboranes
作者:Yu Chen、Yik Ki Au、Yangjian Quan、Zuowei Xie
DOI:10.1007/s11426-018-9388-3
日期:2019.1
B–H functionalization has been achieved. Under the assistance of a bidentate directing group, Cu-catalyzed [4+2] annulation of carboranyl amides with internal alkynes affords unprecedented C,B-substituted carborane-fused-pyridone derivatives, whereas the use of terminal alkynes leads to B–H/C(sp)–H dehydrocoupling products. The isolation and structural identification of a notably stable Cu(I) intermediate
Pd- and Ni-Catalyzed Cross-Coupling Reactions of Functionalized Organozinc Reagents with Unsaturated Thioethers
作者:Laurin Melzig、Albrecht Metzger、Paul Knochel
DOI:10.1002/chem.201002850
日期:2011.3.1
serve as electrophiles in this cross‐coupling reaction. Aryl‐, heteroaryl‐, benzylic, and alkylzinc halides with sensitive functionalities, such as ester, nitrile, or ketone groups react at ambient temperature with unsaturated thioethers using a Ni catalyst. The corresponding Pd‐catalyzed reactions require slightly higher temperatures. Large‐scale cross‐coupling experiments (10–20 mmol) with N‐heterocycles
Traceless Directing Strategy: Efficient Synthesis of N-Alkyl Indoles via Redox-Neutral C–H Activation
作者:Chengming Wang、Yong Huang
DOI:10.1021/ol402523x
日期:2013.10.18
general protocol for the synthesis of N-alkyl indoles has been developed via a redoxneutral C–H activation strategy using a traceless nitroso directinggroup. A broad scope of substituted N-alkyl indoles has been prepared in good to excellent yields using a very simple Rh catalyst system in the absence of an external oxidant or any other additive. Good to excellent regioselectivity has been achieved for