The bioconjugation of hydroxamic acids to antibodies has been made possible through a non-cleavable linker based on the p-mercaptobenzyl alcohol structure that releases hydroxamates in the cells.

This paper is dedicated to Professor Franco Cozzi on his 70th Birthday. We report here a short enantioselective synthesis of Ozanimod, a potent modulator of the enzyme Sphingosine-1-phosphate receptor (S1P R), recently approved by FDA and EMA for the treatment of relapsing-remitting multiple sclerosis. Amongst different synthetic approaches explored, we achieved the best result introducing the stereogenic centre in the last step through imine asymmetric transfer hydrogenation (ATH) using Wills' catalysts. Besides the reduced numbers of enantiomeric purity controls required, this process culminates in an exceptionally high enantioselective reductive amination obtained with commercially available tethered Ru catalysts. Starting from commercially available 4-cyano-indanone, enantiomerically pure Ozanimod was obtained in 5 steps in 62 % overall yield and 99 % ee.