Evans David A, Fandrick Keith R
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Org Lett. 2006 May 25;8(11):2249-52. doi: 10.1021/ol060576e.
[reaction: see text] Enantioselective additions of pyrroles to alpha,beta-unsaturated 2-acyl imidazoles catalyzed by the bis(oxazolinyl)pyridine-scandium(III) triflate complex (1) have been accomplished. The alpha,beta-unsaturated 2-acyl imidazoles were synthesized in high yields through Wittig olefination. A short, enantioselective synthesis of the alkaloid (+)-heliotridane has been accomplished utilizing this methodology and a 2-acyl imidazole cleavage and cyclization. This methodology was then extended to the one-pot asymmetric synthesis of 2-substituted indoles.
[反应：见正文] 已实现由双（恶唑啉基）吡啶-三氟甲磺酸钪（III）配合物（1）催化的吡咯对α，β-不饱和2-酰基咪唑的对映选择性加成反应。通过维蒂希烯烃化反应以高产率合成了α，β-不饱和2-酰基咪唑。利用该方法以及2-酰基咪唑的裂解和环化反应，已完成了生物碱（+）-天芥菜丹的简短对映选择性合成。然后将该方法扩展至2-取代吲哚的一锅法不对称合成。
