Modular asymmetric synthesis of P-chirogenic beta-amino phosphine boranes

Journal article, 2008

(Chemical Equation Presented) A short concise route to β- aminophosphine boranes is presented via the desymmetrization of prochiral phosphine boranes, forming P-chirogenic aldehydes that are rapidly transformed to the target compounds employing reductive amination under microwave irradiation. This sequence provides a modular route to P-chirogenic P,N ligands, and in addition, the intermediate aldehydes are versatile P-chiral building blocks for ligand design in general. An alternative pathway via the corresponding α-carboxyphosphines is also described. The ligands were subsequently evalutated in the asymmetric conjugate addition of diethylzinc to trans-β-nitrostyrene. © 2008 American Chemical Society.