Facile Synthesis of β-Tribromomethyl and Dibromomethylenated Nitroalkanes via Conjugate Addition of Bromoform to Nitroalkenes
作者:Bichismita Sahu、Guddeangadi N. Gururaja、Shaikh M. Mobin、Irishi N. N. Namboothiri
DOI:10.1021/jo802274q
日期:2009.3.20
Addition of bromoform to conjugated nitroalkenes in the presence of Mg provided β-tribromomethyl nitroalkanes in good to excellent yields and diastereoselectivity. These novel Michael adducts, formed under radical conditions, underwent elimination of HBr in the same pot under reflux to afford β-dibromomethylenated nitroalkanes in good yield. Alternatively, a one-pot high yielding synthesis of the dibromides
在镁的存在下,将溴仿加到共轭硝基烯烃中,可提供很好的产率和非对映选择性的β-三溴甲基硝基烷。在自由基条件下形成的这些新颖的迈克尔加合物,在回流下在相同的釜中进行了HBr的消除,从而以良好的收率得到了β-二溴甲基化的硝基烷。备选地,在阴离子条件下,通过LDA介导的溴仿向硝基烯烃的加成,一锅法高产率地合成二溴化物是可能的。