Highly Substituted 2,3-Dihydroisoxazoles by Et<sub>3</sub>N-Catalyzed Tandem Reaction of Electron-Deficient 1,3-Conjugated Enynes with Hydroxylamines
作者:Xiuzhao Yu、Bo Du、Kai Wang、Junliang Zhang
DOI:10.1021/ol100490y
日期:2010.4.16
reaction of electron-deficient 1,3-conjugated enynes with hydroxylamines was developed which provided rapid, metal-free, and regioselective access to highly substituted multifunctionalized 2,3-dihydroisoxazoles under mild conditions. The reactions of 3-(2-arylethynyl)-4H-chromen-4-ones with hydroxylamines afford β-amino enones under the same reaction conditions.
describe a general and efficient protocol for the synthesis of organophosphine compounds from phenols and phosphines (R2PH) via a metal-free C–O bond cleavage and C–P bond formation process. This approach exhibits broad substrate scope and excellent functional group tolerance. The synthetic utilities of this protocol were demonstrated by the synthesis of chiral ligands via the various transformations
Gold(I)‐Catalyzed Highly Diastereo‐ and Enantioselective Cyclization–[4+3] Annulation Cascades between 2‐(1‐Alkynyl)‐2‐alken‐1‐ones and Anthranils
作者:Rahul Dadabhau Kardile、Tzu‐Hsuan Chao、Mu‐Jeng Cheng、Rai‐Shung Liu
DOI:10.1002/anie.202001854
日期:2020.6.22
This work reports gold‐catalyzed [4+3]‐annulations of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with anthranils to yield epoxybenzoazepine products with excellent exo ‐diastereoselectivity (dr>25:1). The utility of this new gold catalysis is manifested by applicable substrates over a broad scope. More importantly, the enantioselective versions of these [4+3]‐cycloadditions have been developed satisfactorily with
A gold(I)‐catalyzed asymmetric intermolecular tandem [3+3]‐cyclization reaction of 2‐(1‐alkynyl)‐2‐ alken‐1‐ones with nitrones has been developed by using Ming‐Phos as a chiral ligand. This method enables access to the stereodivergent synthesis of highly substituted furo[3,4‐d][1,2]oxazines in excellent efficiency and stereoselectivity (up to 99% yield, 99% ee, >20 : 1 dr).
通过使用Ming-Phos作为手性配体开发了金(I)催化的2-(1-炔基)-2-链烯-1-酮与硝酮的不对称分子间串联[3 + 3]环化反应。该方法能够以优异的效率和立体选择性(高达99%的收率,99%ee,> 20:1 dr)获得高度取代的呋喃[3,4- d ] [1,2]恶嗪的立体发散性合成。
Diastereo- and Enantioselective Gold(I)-Catalyzed Intermolecular Tandem Cyclization/[3+3]Cycloadditions of 2-(1-Alkynyl)-2-alken-1-ones with Nitrones
The mysterious cyclizations of gold: An asymmetric gold(I)‐catalyzed formal [3+3] cycloaddition of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with nitrones has been developed. Compound 1 was found to be an effective and reliable chiral catalyst, as well as the commonly used 2, for this gold‐catalyzed reaction. Tf=trifluoromethanesulfonyl.