Stereodivergent Synthesis of Carbocyclic Quaternary <scp>α‐Amino</scp> Acid Derivatives Containing Two Contiguous Stereocenters
Cong Fu, Qi Xiong, Lu Xiao, Ling He, Tian Bai, Zongpeng Zhang, Xiu‐Qin Dong, Chun‐Jiang Wang
Abstract
Comprehensive Summary A novel approach to stereodivergent synthesis of carbocyclic α‐quaternary amino acid derivatives, bearing two contiguous stereocenters, is proposed through sequential dual Cu/Ir‐catalyzed asymmetric allylation and ring‐closing metathesis. A variety of five and six‐membered carbocyclic α‐quaternary amino acid derivatives could be readily achieved in good to high yields with exclusive regioselectivities, excellent diastereoselectivities (13: 1‐ > 20 : 1 dr) and enantioselectivities (generally >99% ee). Of particular note is that the current protocol is also a versatile synthetic tool for the stereodivergent construction of the challenging seven and eight‐membered carbocyclic α‐amino acid derivatives. All four stereoisomers of these important molecules could be precisely synthesized through the permutation of chiral Cu/Ir catalytic system. The power of this strategy has been demonstrated for the facile access to some biologically active chiral molecules, such as spiro‐hydantoins.