Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, India.
Org Biomol Chem. 2010 Nov 7;8(21):4867-73. doi: 10.1039/c0ob00062k. Epub 2010 Aug 24.
Reaction of nitroalkenes or nitrodienes with methyl vinyl ketone (MVK) or acrylate in the presence of the imidazole-LiCl catalyst system provides Rauhut-Currier (vinylogous Morita-Baylis-Hillman) adducts in moderate yield. Under similar conditions (imidazole-hydroquinone), nitroalkenes and nitrodienes undergo self-dimerization to afford the Rauhut-Currier adducts in varying yields. An alternative self-dimerization-nitro group elimination pathway in the presence tricyclohexylphosphine was observed with heteroaromatic nitroalkenes. A synthetically useful one-pot two step transformation of Rauhut-Currier adducts of nitroalkenes with MVK to 2,3-disubstituted cyclopentenones is also described.
硝基亚乙烯基化合物或硝二烯与甲基乙烯基酮（MVK）或丙烯酸盐在咪唑-氯化锂催化剂体系的存在下反应，以中等产率提供 Rauhut-Currier（乙烯基 Morita-Baylis-Hillman）加成物。在类似的条件下（咪唑-对苯二酚），硝基亚乙烯基化合物和硝二烯经历自身二聚化，以不同的产率得到 Rauhut-Currier 加成物。在三环己基膦存在下，观察到杂芳族硝基亚乙烯基化合物的另一种自身二聚化-硝基消除途径。还描述了硝基亚乙烯基化合物与 MVK 的 Rauhut-Currier 加成物到 2,3-二取代环戊烯酮的合成上有用的一锅两步转化。
