Direct Regiospecific and Highly Enantioselective Intermolecular a-Allylic Alkylation of Aldehydes by a Combination of Transition-Metal and Chiral Amine Catalysts

作者：Afewerki Samson; Ibrahem Ismail^*; Rydfjord Jonas; Breistein Palle; Cordova Armando

来源：Chemistry - A European Journal, 2012, 18(10): 2972-2977.

DOI：10.1002/chem.201103366

• aldehydes
• allylation
• asymmetric catalysis
• co-catalysis
• transition metals

The first direct intermolecular regiospecific and highly enantioselective a-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd0 complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecific a-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 e.r.; e.r.=enantiomeric ratio). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals, 2-alkyl-butane-1,4-diols, and amines. The concise co-catalytic asymmetric total syntheses of biologically active natural products (e.g., Arundic acid) are disclosed.

• 出版日期2012-3