College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, P. R. China.
Fachbereich Chemie, Philipps-Universität Marburg , Hans-Meerwein-Strasse 4, 35043 Marburg, Germany.
Org Lett. 2017 Jan 6;19(1):222-225. doi: 10.1021/acs.orglett.6b03500. Epub 2016 Dec 27.
A chiral-at-metal bis-cyclometalated iridium complex combines electrophile activation via metal coordination with nucleophile activation through hydrogen bond formation. This new bifunctional chiral Lewis acid/hydrogen-bond-mediated catalyst permits the challenging enantioselective 2-alkylation of 3-substituted indoles with α,β-unsaturated 2-acyl imidazoles in up to 99% yield and with up to 98% enantiomeric excess at a catalyst loading of 2 mol %. As an application, the straightforward synthesis of a chiral pyrrolo[1,2-a]indole is demonstrated.
一种手性金属双环金属铱配合物通过金属配位激活亲电试剂，并通过氢键形成激活亲核试剂。这种新的双功能手性路易斯酸/氢键介导的催化剂允许具有挑战性的对映选择性的 3-取代吲哚与α，β-不饱和 2-酰基咪唑的 2-烷基化反应，在催化剂负载量为 2mol%时，产率高达 99%，对映过量高达 98%。作为一种应用，展示了一种手性吡咯并[1,2-a]吲哚的简单合成方法。
