Cu(I)/bis(azaferrocene)-catalyzed enantioselective synthesis of β-lactams via couplings of alkynes with nitrones
Cu(I)/bis(azaferrocene)-catalyzed enantioselective synthesis of β-lactams via couplings of alkynes with nitrones
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DOI：
10.1021/ja025833z
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发表时间：
2002-05-01
影响因子：
15
通讯作者：
Fu, GC
中科院分区：
文献类型：
--
作者：
Lo, MMC;Fu, GC
由于β-内酰胺具有广泛的意义（例如，用作药物和手性构建块），人们已致力于开发其立体选择性合成方法。虽然已经取得了相当大的进展，但几乎所有已描述的方法都是基于使用手性前体；直接催化对映选择途径β-内酰胺是罕见的，而且范围有限。在这篇文章中，我们建立了使用一种新的c2对称平面手性双氮杂二烯配体，我们可以通过催化Kinugasa反应（炔与氮酮的偶联）产生具有非常好的对映体过量和顺式非对映选择的β-内酰胺。这一过程吸引人的特点包括起始材料的现成可用性、反应的官能团耐受性和方法的收敛性。
As a consequence of the wide-ranging significance of β-lactams (e.g., use as drugs and as chiral building blocks), a great deal of effort has been dedicated to the development of methods for their stereoselective synthesis. Although considerable progress has been achieved, nearly all of the approaches that have been described are based on the use of chiral precursors; direct catalytic enantioselective routes to β-lactams are rare as well as limited in scope. In this communication, we establish that, using a newC2-symmetric planar-chiral bis(azaferrocene) ligand, we can generate β-lactams with very good enantiomeric excess and cis diastereoselection via catalytic enantioselective Kinugasa reactions (couplings of alkynes with nitrones). Appealing attributes of this process include the ready availability of the starting materials, the functional-group tolerance of the reaction, and the convergency of the approach.