Enantioselective Synthesis and Photoracemization Studies of (+)-2-Cyclopropyl-7,8-dimethoxy-2H- chromene-5-carboxylic Acid Methyl Ester, an Advanced Intermediate of a Dihydrofolate Reductase Inhibitor
Novel Microwave-Assisted One-Pot Synthesis of Isoxazoles by a Three-Component Coupling-Cycloaddition Sequence
作者:Thomas Müller、Benjamin Willy、Frank Rominger
DOI:10.1055/s-2007-1000856
日期:2008.1
The consecutive Sonogashira coupling of acid chlorides with terminal alkynes, followed by 1,3-dipolar cycloaddition under dielectric heating of in situ generated nitrile oxides from hydroximinoyl chlorides furnishes isoxazoles in moderate to good yields in the sense of a one-pot three-component reaction.
5-Hydroxyindoles by Intramolecular Alkynol–Furan Diels–Alder Cycloaddition
作者:Matthew LaPorte、Ki Bum Hong、Jie Xu、Peter Wipf
DOI:10.1021/jo3022605
日期:2013.1.4
A convergent approach provides a convenient access to synthetically and biologically useful 3,4-disubstituted 5-hydroxyindoles. The one-pot procedure uses microwave heating to initiate an intramolecular [4 + 2]-cycloaddition of an alkynol segment onto a furan followed by a fragmentation, aromatization, and N-Boc deprotection cascade. Yields range from 15 to 74%, with aromatic substituents providing better conversions. 4-Trimethylsilylated analogues undergo a 1,3-silatropic rearrangement to give the O-TMS ethers.
Synthesis of Highly Functionalized 4-Iodo-7-azaindazoles via Condensation/Diels–Alder/Retro-Diels–Alder Cyclization of Iodoalkynones and 2-Hydrazineylpyrimidines
作者:Elizabeth C. Swift、Zachary S. Sales、Dongpei Wu、Anastassia Matviitsuk、Daniel J. Pippel、Terry P. Lebold
DOI:10.1021/acs.orglett.3c03481
日期:2023.12.8
Enantioselective Synthesis and Photoracemization Studies of (+)-2-Cyclopropyl-7,8-dimethoxy-2<i>H</i>- chromene-5-carboxylic Acid Methyl Ester, an Advanced Intermediate of a Dihydrofolate Reductase Inhibitor