N-Tosyl-α-aminonitriles have been synthesised by a Strecker reaction of various N-tosyl aldimines with trimethylsilyl cyanide in the presence of catalytic amount of Amberlyst-15 polymer at room temperature under heterogeneous conditions.
NHC-Mediated Stetter-Aldol and Imino-Stetter-Aldol Domino Cyclization to Naphthalen-1(2<i>H</i>)-ones and Isoquinolines
作者:Debabrata Barman、Tanmoy Ghosh、Krishanu Show、Sudipto Debnath、Tapas Ghosh、Dilip K. Maiti
DOI:10.1021/acs.orglett.1c00337
日期:2021.3.19
N-Heterocyclic carbene-catalyzed tandem Stetter-aldol reaction of phthalaldehyde and α,β-unsaturated ketimines has been developed to afford functionalized naphthalen-1(2H)-one derivatives as the formal [4+2] annulation product. Interestingly, the reaction of aldimines led to the formation of isoquinoline derivatives instead of the expected indanone derivatives as a [4+1] annulation product.
Treatment of N-tosylaldimines with acetophenone at room temperature in the presence of Bf(3)center dot OEt2 as a catalyst furnished the corresponding N-tosyl beta-amino ketones in high yields (77-86%) within 6-9 h. Subsequent reduction and cyclization of these compounds afforded 2,4-disubstituted N-tosylazetidines, comprising a three-step, high-yielding synthesis starting from aldimines.