Catalytic bimetalic [Pd(0)/Ag(I) Heck-1,3-dipolar cycloaddition cascade reactions accessing spiro-oxindoles. Concomitant in situ generation of azomethine ylides and dipolarophile
作者:Emma L. Millington、H. Ali Dondas、Colin W.G. Fishwick、Colin Kilner、Ron Grigg
DOI:10.1016/j.tet.2018.05.017
日期:2018.7
Spiro-oxindoles, epi-Spirotryprostatin A and its analogues were prepared from a tactical combination of cascade catalytic bimetallic Pd (0)/Ag(I), intramolecular Heck and subsequent imine → azomethineylide → 1,3-Dipolar cycloadditionreactions. The cascade features in situ generation of azomethineylides and dipolarophiles and produces two new rings together with three stereocentres in good to excellent
作者:Paul W. Groundwater、Toqir Sharif、Andrea Arany、David E. Hibbs、Michael B. Hursthouse、Miklòs Nyerges
DOI:10.1016/s0040-4039(97)10821-8
日期:1998.3
A novel synthesis of didehydroamino acid (DDAA) esters 4 is described, starting from aldimines 1. The mechanism for this reaction involves the cycloaddition of an azomethineylide 2 to an imine 1, followed by the base-catalysed ring-opening of the imidazolidine intermediate 6. This method has also been extended to the synthesis of DDAA esters 4h-j catalysed by an imine 1a.