The ‘Azirine/Oxazolone Method’ on Solid Phase: Introduction of Variousα,α-Disubstitutedα-Amino Acids
作者:Simon Stamm、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.200690019
日期:2006.1
been synthesized from the N- to the C-terminus by the ‘azirine/oxazolone method’ under solid-phase conditions. In this convenient method for the synthesis of sterically demanding peptides on solid-phase, 2H-azirin-3-amines are used to introduce the α,α-disubstituted α-amino acids without the need for additional reagents. Furthermore, the synthesis of poly(Aib) sequences has been explored.
Diazo-Transfer Reaction with Diphenyl Phosphorazidate
作者:Jos� M. Villalgordo、Adelheid Enderli、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.19950780807
日期:1995.12.13
Diphenyl phosphorazidate (DPPA) was used as the azide source in a one-pot synthesis of 2,2-disubstituted3-amino-2H-azirines 1 (Scheme 1). The reaction with lithium enolates of amides of type 2, bearing two substituents at C(2), proceeded smoothly in THF at 0°; keteniminium azides C and azidoenamines D are likely intermediates. Under analogous reaction conditions, DPPA and amides of type 3 with only
A Novel Synthesis of 2,2-Disubstituted 3-Amino-2H-azirines Based on the Reaction between Amide Enolates and Diphenyl Phosphorochloridate
作者:Jos� M. Villalgordo、Heinz Heimgartner
DOI:10.1002/hlca.19930760809
日期:1993.12.15
A novel synthesis of 2,2-disubstituted 3-amino-2H-azirines based on the reaction between amide enolates and diphenyl phosphorochloridate (DPPCl), followed by treatment with NaN3 is presented. The yields obtained in general are excellent, and the method is suitable for laboratory-scale preparations as well as for larger amounts.
Synthesis of Cyclic Depsipeptides and Peptidesvia Direct Amide Cyclization
作者:Jos� M. Villalgordo、Heinz Heimgartner
DOI:10.1002/hlca.19970800312
日期:1997.5.12
depsipeptides and peptides derived from salicylic acids 6 and anthranilic acid 19, respectively (Schemes 2--4 and 5, resp.). The combination of the ‘azirine/oxazolonemethod’ for the synthesis of linear peptidescontaining α,α-disubstituted α-amino acids and the acid-catalyzed amide cyclization in DMF at 60° proved to be an excellent preparative route to ten-membered cyclic depsipeptides and peptides. In the
2,2-二取代的2 H -azirin-3-amines 7(2,2-二取代的3-amino-2 H -azirines)被用作氨基酸合成子,用于制备中等大小的环二肽和水杨酸6和邻氨基苯甲酸19分别(方案2--4和5)。事实证明,将“叠氮基/恶唑酮法”用于合成含有α,α-二取代α-氨基酸的线性肽和酸催化的酰胺在DMF中于60°环化是一种极好的制备十元环的方法十肽和肽。在邻氨基苯甲酸衍生物的情况下,观察到跨环闭环反应(24 25)。较大的环被证明对水解极其敏感。
Synthesis of Enniatin-like Cyclic Depsipeptidesvia ‘Direct Amide Cyclization’
作者:Peter Köttgen、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.200690069
日期:2006.4
The synthesis of several 18-membered cyclodepsipeptides with an alternating sequence of α,α-disubstituted α-amino acids and α-hydroxy acids (compounds 14a–14e) is described. The ring closure via macrolactonization was accomplished by treatment of a diluted suspension of the corresponding linear precursors 12a–12e in toluene with HCl gas, i.e., the so-called ‘direct amide cyclization’. The incorporation