Stereoselective Synthesis of Dienes from N-Allylhydrazones
摘要:
A new method for the stereoselective synthesis of dienes from aldehydes and N-allylhydrazine derivatives has been developed. High levels of (E)-stereoselectivity are obtained for a variety of substrates. Addition of a dienophile to the reaction mixture allows a one-flask diene synthesis-cycloaddition sequence.
Tandem Carbon−Carbon and Carbon−Chlorine Bond Formation by Cu(II) Chloride-Promoted [3,3] Sigmatropic Rearrangement of <i>N</i>-Allylhydrazones
作者:Devon A. Mundal、Jennifer J. Lee、Regan J. Thomson
DOI:10.1021/ja7101967
日期:2008.1.30
chloride-promoted rearrangement of N-allylhydrazones has been developed. Treatment of a number of aromatic N-allylhydrazones with copper(II) chloride provides the formation of both a new carbon−carbon bond and a carbon−chlorine bond in the same reaction. Substrate studies revealed that the carbon−carbon bond-forming step proceeds by way of a concerted [3,3] sigmatropicrearrangement and selectively generates
已开发出一种新的氯化铜 (II) 促进的 N-烯丙基腙重排。用氯化铜 (II) 处理许多芳香族 N-烯丙基腙在同一反应中形成新的碳-碳键和碳-氯键。底物研究表明,碳-碳键形成步骤通过协调一致的 [3,3] σ 重排进行,并选择性地生成反式取代的烯烃。
Stereoselective Synthesis of Dienes from <i>N</i>-Allylhydrazones
作者:Devon A. Mundal、Kelly E. Lutz、Regan J. Thomson
DOI:10.1021/ol802585r
日期:2009.1.15
A new method for the stereoselective synthesis of dienes from aldehydes and N-allylhydrazine derivatives has been developed. High levels of (E)-stereoselectivity are obtained for a variety of substrates. Addition of a dienophile to the reaction mixture allows a one-flask diene synthesis-cycloaddition sequence.
Triflimide-catalysed sigmatropic rearrangement of N-allylhydrazones as an example of a traceless bond construction
作者:Devon A. Mundal、Christopher T. Avetta、Regan J. Thomson
DOI:10.1038/nchem.576
日期:2010.4
The recognition of structural elements (that is, retrons) that signal the application of specific chemical transformations is a key cognitive event in the design of synthetic routes to complex molecules. Reactions that produce compounds without an easily identifiable retron, by way of either substantial structural rearrangement or loss of the atoms required for the reaction to proceed, are significantly more difficult to apply during retrosynthetic planning, yet allow for non-traditional pathways that may facilitate efficient acquisition of the target molecule. We have developed a triflimide (Tf2NH)-catalysed rearrangement of N-allylhydrazones that allows for the generation of a sigma bond between two unfunctionalized sp3 carbons in such a way that no clear retron for the reaction remains. This new âtracelessâ bond construction displays a broad substrate profile and should open avenues for synthesizing complex molecules using non-traditional disconnections. A triflimide-catalysed rearrangement of N-allylhydrazones has been developed that allows for the generation of a sigma bond between two unfunctionalized sp3 carbons such that no clear marker remains for how the bond was formed. This traceless bond construction offers new avenues for convergent fragment coupling in synthetic strategies.