•Various azidomethyl sulfides were prepared via Pummerer rearrangement using p-NO2DPPA.•Methyl sulfoxides were easily converted into the corresponding azidomethyl sulfides.•Azidosulfides could be prepared without the use of toxic or explosive azide sources.•Bioactive compounds were prepared using the synthesized azidomethyl sulfide.A novel method for the synthesis of azidomethyl sulfides by Pummerer rearrangement using bis(p-nitrophenyl) phosphorazidate (p-NO2DPPA) as an azidation reagent was developed. Various methyl sulfoxides were converted into the corresponding azidomethyl sulfides. Importantly, this reaction enables the preparation of azidomethyl sulfides without the use of toxic or explosive azide sources.Download high-res image (54KB)Download full-size image

A fluorous Grubbs–Hoveyda metathesis catalyst supported on Teflon® powder, that readily moves between the solid phase (Teflon®) and the liquid phase (DMF) was prepared. By modulating the hydrophobicity of the reaction medium at the end of the reaction, the supported catalyst could be recovered by simple filtration even though the catalyst existed in a homogeneous state during the reaction. In RCM reactions, the catalyst could be reused up to three times with only a slight loss in reactivity with each subsequent cycle.

A novel method for the SN2 reaction on quaternary carbon atoms using bis(p-nitrophenyl)phosphorazidate has been developed. Chiral tertiary alcohols were directly converted into the corresponding chiral tertiary azides with complete inversion of configuration. Several α,α-disubstituted α-amino esters or amino acids were prepared through the conversion of azides to the corresponding amines by catalytic hydrogenation.

An optimized, multi-gram scale synthesis of fluorous-Fmoc reagents is described. Fmoc reagents bearing C3F7, C4F9, and C6F13 chains were prepared on multi-gram scale (ca. 1.0–7.0 g) in eight steps with overall yields of 73%, 60%, and 90%, respectively. The order of addition of the fluorous alkenes in a one-pot double tagging Heck reaction was also investigated in order to conduct an encoded mixture synthesis of f-Fmoc reagents. The target f-Fmoc reagents bearing C3F7, C4F9, and C6F13 chains could be effectively separated based on the fluorine content of the molecules.

The asymmetric epoxidation of aromatic olefins using optically active first generation manganese salen catalysts and light fluorous variants was examined. Although a slight decrease in the enantioselectivity of the product was observed when light fluorous catalysts were employed, the activities of these catalysts were higher than those of the non-fluorous catalysts. Additionally the influence on enantioselectivity of the oxidation was examined when fluorous cosolvents were used. The enantioselectivity of the oxidation increased with the addition of benzotrifluoride (BTF) regardless of whether a fluorous or non-fluorous salen catalyst was used.

The concise synthesis of fluorous Fmoc (f-Fmoc) reagents bearing C3F7 or C4F9 or C6F13 chains were achieved by fluorous mixture synthesis. The fluorous tagging process was effectively conducted using Heck type reaction of the bis-diazonium salt and the corresponding fluorous olefine, each bearing a different fluorous tag, by a one-pot double tagging strategy. At the final stage, each f-Fmoc reagent was separated from the mixture of three f-Fmoc reagents by fluorous solid phase extraction.

A concise liquid-phase combinatorial synthesis of all stereoisomers of Tenuecyclamide A was achieved using a mixture of d-/l-alanine with each stereoisomer encoded by a different f-Fmoc tag. The synthetic strategy using f-Fmoc reagents as the protecting group for amino acids has been demonstrated to be a useful method for diverse polypeptide analogue synthesis.