An Efficient Synthesis of Coumestrol and Coumestans by Iodocyclization and Pd-Catalyzed Intramolecular Lactonization
摘要:
The iodocyclization of acetoxy-containing 2-(1-alkynyl)anisoles and subsequent direct palladium-catalyzed carbonylation/lactonization provide an efficient route to naturally occurring coumestan and coumestrol, and their related analogues.
An Efficient Synthesis of Coumestrol and Coumestans by Iodocyclization and Pd-Catalyzed Intramolecular Lactonization
摘要:
The iodocyclization of acetoxy-containing 2-(1-alkynyl)anisoles and subsequent direct palladium-catalyzed carbonylation/lactonization provide an efficient route to naturally occurring coumestan and coumestrol, and their related analogues.
Molecular iodine in isopropenyl acetate (IPA): a highly efficient catalyst for the acetylation of alcohols, amines and phenols under solvent free conditions
作者:Naseem Ahmed、Johan E. van Lier
DOI:10.1016/j.tetlet.2006.05.122
日期:2006.7
Iodine in isopropenyl acetate (IPA) is a highly efficientcatalyst for the acetylation of a variety of alcohols, phenols and amines undersolventfree conditions. Primary, secondary, tertiary alcohols, amines and mono to polyhydroxy phenols and anilines with electron donating or withdrawing substituents can be easily acetylated in good to excellent yield at 85–90 °C.
Synthesis of 2,3-Disubstituted Benzo[<i>b</i>]furans by the Palladium-Catalyzed Coupling of <i>o-</i>Iodoanisoles and Terminal Alkynes, Followed by Electrophilic Cyclization
作者:Dawei Yue、Tuanli Yao、Richard C. Larock
DOI:10.1021/jo051299c
日期:2005.12.1
2,3-Disubstitutedbenzo[b]furans are readily prepared under very mild reaction conditions by the palladium/copper-catalyzed cross-coupling of various o-iodoanisoles and terminalalkynes, followed by electrophilic cyclization with I2, PhSeCl, or p-O2NC6H4SCl. Aryl- and vinylic-substituted alkynes undergo electrophilic cyclization in excellent yields. Biologically important furopyridines can be prepared
2,3-二取代的苯并[ b ]呋喃很容易在很温和的反应条件下通过钯/铜催化的各种邻碘苯甲醚和末端炔的交叉偶联反应,然后用I 2,PhSeCl或p-进行亲电环化而制得。 O 2 NC 6 H 4 SCl。芳基和乙烯基取代的炔烃以优异的收率进行亲电子环化。生物学上重要的呋喃吡啶可以通过这种方法以高产率制备。