Asymmetric aza-Diels-Alder reaction: enantio- and diastereoselective reaction of imine mediated by Chiral Lewis acid
作者:Kouji Hattori、Hisashi Yamamoto
DOI:10.1016/s0040-4020(01)80532-9
日期:1993.2
asymmetric aza-Diels-Alder reaction usingchiral boron mediator is developed. The key to its success is the use of the chiral boron complex prepared in situ from (R)- or (S)- binaphthol and B(OPh)3. The enantiomeric reaction of prochiral imine affords products of up to 90% ee. The double asymmetric induction of chiral imine using α-benzylamine as a chiralauxiliary is achieved with almost complete diastereoselectivity
tested as chiral auxiliaries in the stereoselectivesynthesis of β-lactams by condensation of the titanium enolates of 2-pyridyl thioesters with chiral imines. The amines were selected among the following classes of compounds: benzylic amines, β-aminoalcohols, β-heterosubstituted α-aminoesters. Inexpensive and available in both enantiomeric forms α-methylbenzylamine was identified as the chiral auxiliary
Diastereoselective addition of higher order cuprates and zinc-copper reagents to imines derived from (S)-1-phenylethylamine
作者:Marco Bandini、Pier Giorgio Cozzi、Achille Umani-Ronchi、Marzia Villa
DOI:10.1016/s0040-4020(99)00418-4
日期:1999.6
The diastereoselective addition of higher order (H.O.) cuprates and zinc-copper reagents to aliphatic and aromatic chiral iminesderivedfrom (S)-1-phenylethylamine was examined. Aliphatic chiral imines react with (Allyl)2CuCNLi2 and (n-Bu)2Cu(CN)Li2 in the presence of BF3·Et2O and Me3SiCl in high diastereoselection, while c-C6H11Cu(CN)ZnI and AllylCu(CN)ZnBr afford chiral amines in comparable yields