Two buta-2,3-dienylstannanes, 1-tri-n-butylstannylbuta-2,3-diene and 1-triphenylstannylbuta-2,3-diene, have been prepared and shown to react with aldehydes and acetals under Lewis acid catalyzed conditions producing (buta-1,3-dien-2-yl)methanol derivatives in high yields.
Synthetic Method for the Preparation of 2-Aminomethyl-1,3-diene Derivatives through Indium-Mediated 1,3-Butadien-2-ylation of Imines
作者:Dong Seomoon、Jaemyung A、Phil Ho Lee
DOI:10.1021/ol9005213
日期:2009.6.4
An efficient method for the preparation of a variety of 2-aminomethyl-1,3-dienes was developed through the reaction of imines with organoindium reagent generated in situ from indium and 1,3-dibromo-2-butyne. Three-component reactions of aldehydes, amines, and organoindium reagents gave successful results in a one-pot process.
examined establishing an efficient method for the preparation of alkyl(1,3-butadien-2-yl)methanols. Application of this method to chiral acetals prepared from (R,R)-2,4-pentanediol led to chiral alkyl(1,3-butadien-2-yl)methanol derivatives with high optical purity which were alternatively synthesized by the Sharpless kinetic resolution of racemic alkyl(1,3-butadien-2-yl)methanols.
Diels–Alderreactions of ten 2-substituted buta-1,3-dienes 1a–j with N-phenylmaleimide were examined under various conditions, demonstrating that an allylic heteroatom substiuent at the C-2 position exerts significant directing effect on diastereofacial selection and also that the diastereofacial selectivity can be enhanced by use of 5 mol dm–3 LiClO4–Et2O as a reaction medium.
Game, set, and match: The first regio‐ and enantioselective version of the title reaction is described. The chiral catalyst prepared in situ from CrCl3 and a non‐C2‐symmetric bis(oxazoline) ligand 1 affords the valuable chiral β‐allenols regioselectively in good yields with excellent ee values. R=aryl, alkyl.