Organic Syntheses via Transition-Metal Complexes. 99.<sup>1</sup> Cyclopentadiene Annelation to Enolizable Cyclic Ketones via (1-Alkynyl)carbene Complexes (M = Cr, W)
作者:Rudolf Aumann、Roland Fröhlich、Jörg Prigge、Oliver Meyer
DOI:10.1021/om9810394
日期:1999.4.1
The procedure for a metal-mediated cyclopentadiene annelation to enolizable cycloalkanones is described. Its key step is based on the cyclization of a 1-metalla-1,3,5-hexatriene intermediate, which is generated from the 1-metalla-1,5-hexadien-3-yne (CO)5MC(OEt)C⋮CC(∼)CH(∼) (3; M = Cr, W) precursor. Addition of secondary amines 4a,b to [2-(1-cyclopentenyl)ethynyl]carbene complexes 3a,b (M = W, Cr) affords
描述了金属介导的环戊二烯脱嵌成可烯丙基环烷酮的步骤。它的关键步骤是基于1-metalla-1,3,5-己三烯中间体的环化反应,该中间体是由1-metalla-1,5-hexadien-3-yne(CO)5 M C(OEt)生成的C = CC(〜)CH(〜)(3; M = Cr,W)前体。将仲胺4a,b加到[2-(1-环戊烯基)乙炔基]卡宾络合物3a,b(M = W,Cr)中,得到4-氨基-1-金属-1,3,5-己三烯(3E) -图5a - d,其自发地环化至η 1(C,M)-环戊二烯配合物6a - d。闭环是高度立体选择性的,并且涉及M C键与1-金属-1,3,5-己三烯单元的末端C C键的抗加成(!)。通过质子化得到化合物6a的配体,得到亚胺盐7a。除了苯胺,化合物3a中,b的产率的4-(NH -氨基)-1- metalla -1,3,5- hexatrienes(3Z) - 10A,b