Regioselective synthesis of spiro quinazolinones via sequential hydroalkoxylation and intramolecular amide-cyclization of alkynol ureas
摘要:
Highly functionalized spiro-furan/pyran quinazolinones employing a cascade hydroalkoxylation-intramolecular amide-cyclization of alkynol ureas in excellent yields and exclusive regioselectivity have been unveiled.
Regioselective Arylative Ring-Closing Reaction of 2-Alkynylphenyl Derivatives: Formation of Arylated Benzoxazin-2-ones, Benzoxazin-2-amines and 2,3-Disubstituted Indoles
作者:Hideki Minami、Takuya Kanayama、Reishi Tanaka、Noriko Okamoto、Takuya Sueda、Reiko Yanada
DOI:10.1002/ejoc.201601162
日期:2016.12
2-alkynylphenylureas with diaryliodonium salts gave C,N-double-arylated benzoxazin-2-ones and C-arylated benzoxazin-2-amines, respectively, both bearing fully substituted exocyclic olefins. On the other hand, the palladium-catalysed arylative ring-closing reaction of 2-alkynylphenylcarbamates gave C-arylated 2,3-disubstituted indoles.
NHC-Stabilized Gold(I) Complexes: Suitable Catalysts for 6-<i>exo</i>-dig Heterocyclization of 1-(<i>o</i>-Ethynylaryl)ureas
作者:Ana Gimeno、Mercedes Medio-Simón、Carmen Ramírez de Arellano、Gregorio Asensio、Ana B. Cuenca
DOI:10.1021/ol100595s
日期:2010.5.7
3-substituted 1-(o-ethynylaryl)ureas 1 selectively undergo either 6-exo-dig or 5-endo-dig cyclization (to give 4-methylene-3,4-quinazolin-2-ones 2 or indoles 3, respectively) depending on the choice of the metal, ligand, and reaction conditions. The best results (up to 96% yield) in the preparation of the hydroamination products 2 are achieved with the highly bulky NHC-stabilized cationic gold(I) complex