posted on 2023-01-05, 21:05authored byJeffrey
R. Groch, Nicholas R. Lauta, Jon T. Njardarson
We
report a detailed study on the synthesis and aldehyde vinylogation
applications of chiral N-sulfinyl imine phosphonate reagents. Two
complementary scalable reagent routes, from trialkyl phosphites and
methyl phosphonates, respectively, are presented. This reagent class
enables significant streamlining in synthesis of conjugated Ellman
imines from aldehydes, which can now be accomplished in a single step
compared to a more classic 4-step redox-based approach. Aldehyde vinylogation
optimizations have revealed significant counterion effects and unexpected
competing reaction challenges that needed to be addressed to achieve
high yields.