Synthesis and catalytic reactivity in Friedel–Crafts acylations of monobridged bis(cyclopentadienyl)molybdenum(I) carbonyl complexes
作者:Xin Long Yan、Ning Zhang、Zhi Qiang Hao、Zhi Hong Ma、Zhan Gang Han、Xue Zhong Zheng、Jin Lin
DOI:10.1016/j.poly.2018.03.021
日期:2018.6
analysis. Friedel–Crafts acylation reactions of anisole derivatives with aromatic or aliphatic acyl chlorides catalyzed by complexes 4–6 showed that all of these monobridged bis(cyclopentadienyl)molybdenumcarbonyl complexes have catalytic activity.
Tetralone Esters as Intermediates for the Synthesis of Podophyllotoxin Derivatives Via Cyclopropanation of Chalcones
作者:N. Nanjundaswamy、S. Shashikanth、C. Anjanamurthy、K. M. Lokanatha Rai
DOI:10.1080/00397910008087138
日期:2000.4
Abstract Cyclopropyl ester (8a-f) were synthesized by the cyclopropanation of chalcones (7a-e) in dry benzene using powdered sodium in 80-85% yield. Preparation of tetralone ester (4a-e), an intermediate for the synthesis of podophyllotoxin derivatives by Lewis acid (SnCl4) catalyzed cyclization of (8a-e) is also described here.
A non-metal catalyzed deamination of propargylamines was achieved by using DBU as the catalyst and water as the carbonyl oxygen atom source. The role of DBU was found to promote the alkyne-allene isomerization process, followed by the hydrolysis to access a wide range of chalcones in good to excellent yields. This newly developed strategy features metal-free, good functional group compatibility, mild