Synthesis of Cyclopentenimines from <i>N</i>-Allyl Ynamides via a Tandem Aza-Claisen Rearrangement–Carbocyclization Sequence
作者:Xiao-Na Wang、Gabrielle N. Winston-McPherson、Mary C. Walton、Yu Zhang、Richard P. Hsung、Kyle A. DeKorver
DOI:10.1021/jo400960e
日期:2013.6.21
of this tandem cascade. With N-sulfonyl ynamides, the use of palladium catalysis is required, as facile 1,3-sulfonyl shifts dominate under thermal conditions. However, since no analogous 1,3-phosphoryl shift is operational, N-phosphoryl ynamides could be used to prepare similar cyclopentenimines under thermal conditions through zwitter ionic intermediates that undergo N-promoted H-shifts. Alternatively
我们在这里描述了我们对N-烯丙基炔酰胺的Pd 催化和热氮杂-克莱森-碳环化以制备各种 α,β-不饱和环戊烯亚胺的研究细节。ynamide 吸电子基团和β-取代基的性质在这种串联级联的成功中起着关键作用。对于N-磺酰基炔酰胺,需要使用钯催化,因为在热条件下容易发生 1,3-磺酰基转移。然而,由于没有类似的 1,3-磷酰基转移是可操作的,N-磷酰基炔酰胺可用于在热条件下通过经历N-促进H 的两性离子中间体制备类似的环戊烯亚胺-转移。或者,通过使用带有系链碳亲核试剂的 ynamides,可以截获两性离子中间体,从而迅速产生更复杂的稠合双环和三环支架。