gold-catalyzed tandem hydration/α-ketol rearrangement of 1-alkynylcyclobutanol derivatives, leading to cyclopentanones bearing an α-hydroxy substituted quaternary center. In the presence of water, coordination of gold catalyst onto alkynyl moiety triggers hydration rather than a direct ringexpansion, which followed by unprecedented Au-catalyzed α-ketol rearrangement. The details and the scope of this method
inherent double controlled strategy of sterically hindered propargyl alcohols without the installing of external directing groups. Its synthetic robustness and practicality have been illustrated by the concise synthesis of bervastatin, a hypolipidemic drug, and late‐stage modification of complex alkynes with precise regioselectivity.
Palladium-catalyzed ring expansion reaction of 1-alkynylcyclobutanols with aryl iodides: an efficient route to 2-disubstituted methylenecyclopentanones
作者:Li-Mei Wei、Li-Lan Wei、Wen-Bin Pan、Ming-Jung Wu
DOI:10.1016/s0040-4039(02)02581-9
日期:2003.1
The reaction of 1-alkynylcyclobutanols with aryl iodides in the presence of Pd(OAc)2 and Et3N in acetonitrile at 80°C for 24 h gives 2-disubstituted methylenecyclopentan-1-ones in modest to good yields. The tandem insertion-ring expansion process proceeds via the formation of an alkynyl π-complex, followed by migration of a carbon-carbon bond of the tert-alkanol to form the cyclopentanones stereoselectively
Ring expansion in the coupling of Fischer-carbene complexes with 1-alkynyl-1-hydroxy cyclic compounds
作者:Metin Zora、James W Herndon、Yuhui Li、Jason Rossi
DOI:10.1016/s0040-4020(01)00359-3
日期:2001.6
The coupling of a variety of transitionmetal–carbenecomplexes with alkynols has been studied. In many cases, the intermediate vinylcarbene complexes formed in this reaction undergo a ring expansion to afford cyclic ketone derivatives. This scope and limit of this process is explored.
Selective Synthesis of Pyrazolo[1,2-<i>a</i>]pyrazolones and 2-Acylindoles via Rh(III)-Catalyzed Tunable Redox-Neutral Coupling of 1-Phenylpyrazolidinones with Alkynyl Cyclobutanols
作者:Yuanshuang Xu、Mengyang Shen、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.orglett.0c01475
日期:2020.6.19
An unprecedented divergent synthesis of pyrazolo[1,2-a]pyrazolones and 2-acylindoles via Rh(III)-catalyzed [4 + 1] or [3 + 2] annulation of 1-phenylpyrazolidinones with alkynyl cyclobutanols through redox-neutral multiple bond activation by using −NH and −OH units as directing groups is presented. Notably, different annulation reactions were selectively achieved by simply adjusting the reaction conditions
通过Rh(III)催化1-苯基吡唑烷二酮与炔基环丁醇通过氧化还原-中性多键的环化反应,空前地合成吡唑并[1,2- a ]吡唑并酮和2-酰基吲哚。提出了通过使用-NH和-OH单元作为导向基团的活化。值得注意的是,通过简单地调节反应条件选择性地实现了不同的环化反应。这些方法具有操作简单,容易获得的底物和高区域选择性/化学选择性等特点,可以在相关领域广泛应用。