Phosphine-Mediated Iterative Arene Homologation Using Allenes

• DOI: 10.1021/jacs.5b07403
• Publication Date: 2015-08-21T16:44:18Z
• Authors: Kui Zhang; Lingchao Cai; Xing Jiang; Miguel A. Garcia-...; Ohyun Kwon
• Keywords: Wittig reaction; Aldol reaction; Umpolung

A PPh3-mediated multicomponent reaction between o-phthalaldehydes, nucleophiles, and monosubstituted allenes furnishes functionalized non-C2-symmetric naphthalenes in synthetically useful yields. When the o-phthalaldehydes were reacted with 1,3-disubstituted presence of PPh2Et, naphthalene derivatives also obtained up to quantitative The mechanism latter transformation is straightforward: aldol addition followed by Wittig olefination dehydration. former a tandem γ-umpolung/aldol/Wittig/dehydration process, as established preparation putative intermediates mass spectrometric analysis. This can be applied iteratively prepare anthracenes tetracenes using carboxylic acids pronucleophiles.