Catalyst-Free\nDomino Cross-Olefinations and Intramolecular\nCyclizations of Morita–Baylis–Hillman Carbonates with\nSulfur Ylides

A novel strategy for the catalyst-free domino cross-olefination\nand intramolecular cyclization of Morita–Baylis–Hillman\ncarbonates with sulfur ylides has been established, resulting in the\nsynthesis of 1,2-dihydroquinolines with a broad scope, excellent chemoselectivity,\nand high efficiency. Mechanistic experiments revealed the process\nof 1,1-dipole cross-olefination and highlighted the assistance of\nthe amino group in achieving successful transformations.