Peptoid-synthesis-inspired modular assembly of azaxylylene precursors and their cyclizations. [a] Acetal hydrolysis step is required only in the a (i.e. benzaldehyde) series. [b] Major diastereomer is shown, the minor hydroxy epimer (not shown) is denoted with a prime, 16’a etc. Bn=benzyl, DIPEA=diisopropylethylamine, PTS=pyridinium para-tolue-nesulfonate.
Condensation of benzil, benzaldehyde, ammonium acetate and n-Pr amine using recycled catalysts.
Scheme of preparation of ligand L.
Potential energy profiles for the addition of benzaldehyde to (TMS)3Si+ and Me3Si+.