Synthesis and molecular structures of novel .alpha.-amino organoaluminum ester enolates. Key intermediates in the selective formation of trans-3-amino-2-azetidinones
作者:Fred H. Van der Steen、Guido P. M. Van Mier、Anthony L. Spek、Jan Kroon、Gerard Van Koten
DOI:10.1021/ja00015a031
日期:1991.7
Full-matrix least-squares refinement on F converged at R = 0.05 1 and R, = 0.043. The structures of enolates 3 and 3’ in solution as well as the reactions of these enolates with imines 4 is discussed. It is shown that both dimeric enolates 3 as well as monomeric adducts 3’ may act as the reactive intermediates in the one-pot synthesis of 3-amino-2-azetidinones 5 and 6, which is characterized by the reactions
本文介绍了新型α-氨基二烷基铝酯烯醇化物的合成、表征和合成应用。使用简单的亚胺,当存在(少量)过量的二烷基氯化铝时,这些原位制备的铝烯醇化物以优异的产率提供具有良好 de's (72-92%) 的反式-3-氨基-2-氮杂环丁酮 5 和 6。LiO(RO)C=C(H)NR1R2(2,R=R1=R2=烷基)与(R3)2AlCl(R3=烷基)的金属转移得到纯的(R3),Al0(RO)C=C(H) NR1R2 (3) 的定量收率。在加入第二当量的 (R3),AICI 后,形成稳定的加合物 (R3),Al0[(RO)C=C(H)NR1R2]+AI(R3)2Cl(3')。在两种类型的烯醇化物中,酯烯醇化物阴离子是通过 AI-0 和配价 AI-N 键与金属中心结合的 N,O-螯合物。因此,这些烯醇的构型是 Z。3b (R = R' = R2 = R3 = Me) 的晶体结构测定显示二聚体缔合物,具有平面骨架,由两个对称相关的