Synthesis of Tetrasubstituted 1,4-Dicarbonyl (<i>Z</i>)-2,3-Dihaloalkenes via Electrophilic Halogenation of Alkynyl Hydrazones
作者:Akashdeep Sharma、Paru Jamwal、Ramani Gurubrahamam
DOI:10.1021/acs.orglett.3c02864
日期:2023.10.6
A highly practical and stereoselective route to 1,4-dicarbonyl 2,3-dihaloalkenes is presented. The strategy involves bench-stable unprotected alkynyl hydrazones and commercially available N-halosuccinimides that provide γ-oxo-α,β-(Z)-dihaloenoates in excellent yields with complete Z-selectivity. The protocol also furnishes vicinal dihaloalkenes with two different halogen atoms. Also, a straightforward
提出了一种高度实用且立体选择性的 1,4-二羰基 2,3-二卤代烯烃合成路线。该策略涉及实验室稳定的未保护的炔基腙和市售的N -卤代琥珀酰亚胺,它们以优异的收率提供具有完全Z选择性的 γ-氧代-α,β-( Z )-二卤代烯酸酯。该方案还提供了具有两个不同卤素原子的邻位二卤代烯烃。此外,还证明了从容易获得的 2-氧代-3-丁酸中直接一锅法合成二卤代烯酸。此外,还探索了 4-oxo-2,3-dibromoenoates 的潜在合成转化,其中包括有价值的五元和六元杂环的合成。