First successful synthesis, isolation and characterization of open-chain 1,2-diazidoethenes
摘要:
Open-chain 1,2-diazidoethenes have been obtained from the recently reported acceptor-substituted propargyl azides by one-pot reactions with tetramethylguanidinium azide (TMGA) and in some cases via a two-step procedure starting with in situ production of the corresponding azidoallene followed by addition of hydrazoic acid with the help of TMGA. In a different synthetic pathway, the substitution reactions between 2-azido-3-haloacroleins and hexadecyltributylphosphonium azide (QN(3)) have been used. In order to have more evidence for their structures, some diazido compounds were converted to their bis-triazole derivatives through 1,3-dipolar cycloaddition. (c) 2005 Elsevier Ltd. All rights reserved.
New Way to Methylene-2H-azirines and Their Use as Powerful Intermediates for the Stereo- and Regioselective Synthesis of Compounds with Vinylamine Substructure
作者:Joseph Rodolph Fotsing、Klaus Banert
DOI:10.1002/ejoc.200600302
日期:2006.8
New and relativelystable methylene-2H-azirines 1 have been prepared by photolysis of allenyl azides or from 2-halo-2H-azirines by elimination of HX (X = halogen). The reaction of these methylene-2H-azirines with nucleophiles led to the highly stereo- and regio-selective formation of novel 1-aminovinyl derivatives with good to excellent yields. The trapping reactions of the less stable methylene-2H-azirines
First Propargyl Azides Bearing Strong Acceptor Substituents and Their Effective Conversion into Allenyl Azides: Influence of the Electronic Effects of Substituents on the Reactivity of Propargyl Azides
作者:Joseph Rodolph Fotsing、Klaus Banert
DOI:10.1002/ejoc.200500135
日期:2005.9
We have succeeded in the synthesis of propargyl azides containing 1- or 3-phenylthio functionalities. The selective oxidation of their sulfur atoms to sulfoxides and sulfones allows access to the first propargyl azides bearing acceptor substituents. Interestingly, the prototropicrearrangement of the latter propargyl azides leads to the formation of allenyl azides with relatively high stabilities and
Open-chain 1,2-diazidoethenes have been obtained from the recently reported acceptor-substituted propargyl azides by one-pot reactions with tetramethylguanidinium azide (TMGA) and in some cases via a two-step procedure starting with in situ production of the corresponding azidoallene followed by addition of hydrazoic acid with the help of TMGA. In a different synthetic pathway, the substitution reactions between 2-azido-3-haloacroleins and hexadecyltributylphosphonium azide (QN(3)) have been used. In order to have more evidence for their structures, some diazido compounds were converted to their bis-triazole derivatives through 1,3-dipolar cycloaddition. (c) 2005 Elsevier Ltd. All rights reserved.