In 2003, Martı ́n et al. reported a green alcohol oxidation with FeBr 3 (cat.)/H 2 O 2 and proposed a high-valent iron species (HIS) responsible for the alcohol oxidation. Reinvestigating this FeBr 3 (cat.)/H 2 O 2 method led us to propose a different mechanism that involves a reactive brominating species (RBS) for the oxidation of alcohols. The evidence to support this RBS-based mechanism includes (1) our recent findings of in situ-generated RBS from the related FeBr 2 /H 2 O 2 or CeBr 3 /H 2 O 2 systems, (2) our results of a series of controlled experiments, and ( 3) some related RBS-based precedents (NBS, NBA, or Br 2 ) showing similar high oxidation selectivity of secondary over primary alcohols. These studies enable us to discover that a RBS from CeBr 3 /H 2 O 2 is much more efficient for the oxidation of secondary and benzylic alcohols, which represents a new green protocol for selective oxidation of alcohols to carbonyls.

Lepadins are cis-fused decahydroquinoline (DHQ) marine alkaloids that have shown diverse biological activities and have attracted extensive synthetic interest. A new collective synthetic strategy is reported that features a green chemistry approach for constructing the common cis-fused DHQ core, which is achieved through green oxone-halide oxidation for both the aza-Achmatowicz rearrangement and the intramolecular [3 + 2] cycloaddition of nitrile oxide–alkene. Collective total syntheses of lepadins A–E and H are accomplished from the common DHQ core within 10 steps.