  Microwave-assisted synthesis of N-heterocyclic carbene precursors; Demonceau, Albert  ; Delaude, Lionel in Synlett (2006), (3), 493-495 A very simple and efficient procedure is reported for the synthesis of 1,3-diarylimidazolinium chlorides by cyclization of N,N'-diarylethylenediamines dihydrochlorides with triethyl ortho-formate under ... [more ▼] A very simple and efficient procedure is reported for the synthesis of 1,3-diarylimidazolinium chlorides by cyclization of N,N'-diarylethylenediamines dihydrochlorides with triethyl ortho-formate under microwave irradiation. [less ▲] Detailed reference viewed: 13 (0 ULg)Catalytic asymmetric dihydroxylation of C,C double bonds with osmium tetroxide using selenoxides as co-oxidants; Colaux, Catherine in Synlett (2001), (4), 501-504 Asymmetric dihydroxylation of olefins has been achieved in good yields and ee's using potassium osmate dihydrate (K2OsO2(OH)(4), the pre-oxidant), (DHQD)(2)PHAL (the chiral ligand), potassium carbonate ... [more ▼] Asymmetric dihydroxylation of olefins has been achieved in good yields and ee's using potassium osmate dihydrate (K2OsO2(OH)(4), the pre-oxidant), (DHQD)(2)PHAL (the chiral ligand), potassium carbonate (the base) and selenoxides (the co-oxidants). Bath the yield and the ee proved to be pH dependent, the highest yield and ee being found at almost the same pH values. The rate of the reaction was found to be highly dependent upon the structure of the selenoxide used. Some representative examples involving aminoxides are presented for comparison. [less ▲] Detailed reference viewed: 4 (1 ULg) |
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