The Ti-mediated reaction of Grignard reagents with nitriles was investigated with sub-stoichiometric amounts of titanium isopropoxide. Cyanoesters were converted to spirocyclopropanelactams in good yields using as low as 0.05 eq of Ti(OiPr)4. Under similar conditions, cyanocarbonates led to spirocyclopropane oxazolidinones and/or aminocyclopropylcarbinols. A very short synthesis of the naturally occurring aminocyclopropanecarboxylic acid illustrates the usefulness of this methodology.
用亚
化学计量的
异丙醇钛研究了
格氏试剂与腈的
钛介导反应。使用低至 0.05 当量的 Ti(OiPr)4,将
氰酯转化为螺环丙内酰胺,收率良好。在类似条件下,
氰基
碳酸酯产生螺
环丙烷恶唑烷酮和/或
氨基
环丙基甲醇。天然存在的
氨基
环丙烷甲酸的非常简短的合成说明了该方法的有用性。