A synergistic rhodium(Ⅱ)/phosphoric acid catalyzed three component reaction of 3-diazooxindoles,alcohols and N-benzhydryl-α-imino ester is developed for the efficient construction of chiral β-alkoxy C~β-tetrasubstituted α-amino acid derivatives in good yields and with excellent diastereoselectivities and high enantioselectivities.The synthetic application of the resulting products was illustrated by reducing with Pd/C under H_2 atmosphere followed reacting with CSCl_2 at room temperature to rapid afford 3-spirocyclic oxindole in a good yield with a chirality retainment.The three-component reaction is proposed to proceed through an electrophilic trapping of the oxonium ylides by N-benzhydryl-α-imino ester. A synergistic rhodium (II) / phosphoric acid catalyzed three component reaction of 3-diazooxindoles, alcohols and N-benzhydryl-α-imino ester is developed for the efficient construction of chiral β-alkoxy C ~ β-tetrasubstituted α-amino acid derivatives in good yields and with excellent diastereoselectivities and high enantioselectivities. The synthetic application of the resulting products was illustrated by reducing with Pd / C under H_2 atmosphere followed reacting with CSCl_2 at room temperature to rapid afford 3-spirocyclic oxindole in a good yield with a chirality retainment The three-component reaction is proposed to proceed through an electrophilic trapping of the oxonium ylides by N-benzhydryl-α-imino ester.