Diastereoselective Synthesis of β-Heteroaryl syn-α-Methyl-β-Amino Acid Derivatives via a Double Chiral Auxiliary Approach
摘要:
The addition of the SuperQuat enolate to five- and six-membered heterocyclic tert-butyl sulfinimines led to a high syn-selectivity of up to 99:1 in good to excellent yields. The reaction Is tentatively proposed to proceed through an open-chain transition state with the presence of an alpha-heteroatom on the sulfinimine leading to high diastereoselectivities. The adducts were derivatized to beta-amino esters and amides in a facile manner.