95242-71-0Relevant academic research and scientific papers
Azetidines and Bisazetidines. Their Synthesis and Use as the Key Intermediates to Enantiomerically Pure Diamines, Amino Alcohols, and Polyamines
Ojima, Iwao,Zhao, Mangzhu,Yamato, Takehiko,Nakahashi, Kazuaki,Yamashita, Mitsuo,Abe, Rumiko
, p. 5263 - 5277 (2007/10/02)
Highly selective reductions of β-lactams (1, 5), direct-tandem bis-β-lactams (6), and tandem bis-β-lactams (7) to the corresponding azetidines (13, 14) and bisazetidines (11, 12) are successfully performed by using diisobutylaluminum hydride (DIBAL-H), monochlorohydroalane (AlH2Cl) and dichloroalane (AlHCl2) as specific reducing agents: Enantiomerically pure azetidines and bisazetidines are readily synthesized without loss of enantiomeric purity.Possible mechanisms that can accomodate the unique selectivity realized by hydroalanes are discussed.Hydrogenolysis of 2-arylazetidines and 2,2'-diarylbisazetidines on palladium catalyst or Ra ney-Ni gives the corresponding diamines, amino alcohols, polyamino alcohols, and polyamino ethers in excellent yields, which may serve as useful chiral chelating agents as well as chiral building blocks for organic synthesis and for chiral macrocycles.
New aspects of β-lactam chemistry: β-lactams as chiral building blocks
Ojima, Iwao,Shimizu, Nobuko,Qiu, Xiaogang,Chen, Hauh-Jyun C.,Nakahashi, Kazuaki
, p. 649 - 658 (2007/10/02)
Recent advances on the new aspects of β-lactam chemistry in which β-lactams are used as chiral building blocks for the synthesis of a variety of α-amino acids, 4α-alkyl-α-aminoacids, oligopeptides, labeled peptides, azetidines, amino alcohols, etc., are reviewed.The topics include new and effective routes to dipeptides via homochiral β-lactams obtained by extremely stereoselective cycloadditions of chiral ketenes to chiral imines, a novel route to labeled peptides through extremely stereoselective and stereospecific reductive cleavage of β-lactams on a palladium catalyst, and new efficient syntheses of α-alkyl-α-amino acids and their peptides by the highly effective asymmetric alkylations of β-lactam lithium enolates followed by hydrogenolysis or Birch reduction.Mechanism of those highly selective unique reactions are discussed.
