Gold(I)-catalyzed intramolecular [4 + 2] cycloaddition of ortho-(N-tethered 1, 6-diynyl)benzaldehydes to 3, 4-dihydrobenzo[f]isoquinolin-1(2H)-ones. Issue 31 (30th July 2020)

• Record Type: Journal Article
• Authors: Zhong, Jiankai; Hu, Rui; Sang, Jingjing; Rao, Weidong
• Is Part Of: Tetrahedron letters. Volume 61:Issue 31(2020)
• Publication Date: 2020-07-30
• Subjects: Gold catalysis -- O-alkynylbenzaldehyde -- [4+2]-cycloaddition -- Benzopyrilium -- 3, 4-dihydrobenzo[f]isoquinolin-1(2H)-one; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2020.152200
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: 3, 4-Dihydrobenzo[ f ]isoquinolin-1( 2H )-ones were synthesized efficiently. An atom-economic approach using readily accessible materials. Low catalyst loading of 2 mol% and mild reaction conditions. The reaction can be scaled-up to gram scale. Abstract: An efficient synthetic method to prepare 3, 4-dihydrobenzo[ f ]isoquinolin-1( 2H )-ones through gold(I)-catalyzed intramolecular [4 + 2] benzannulation of o -( N -tethered 1, 6-diynyl)benzaldehydes at a low catalyst loading of 2 mol% is described. The product of 3, 4-dihydrobenzo[ f ]isoquinolin-1( 2H )-ones can be easily transformed to benzo[ f ]isoquinolin-1-ols by simply treating with phenylmagnesium bromide under mild conditions. The structures of compounds 2o and 2w were also ascertained by X-ray crystallographic analysis.