931-13-5Relevant articles and documents
A phosphonium ylide as a visible light organophotoredox catalyst
Toda, Yasunori,Tanaka, Katsumi,Matsuda, Riki,Sakamoto, Tomoyuki,Katsumi, Shiho,Shimizu, Masahiro,Ito, Fuyuki,Suga, Hiroyuki
supporting information, p. 3591 - 3594 (2021/04/14)
A phosphonium ylide-based visible light organophotoredox catalyst has been designed and successfully applied to halohydrin synthesis using trichloroacetonitrile and epoxides. An oxidative quenching cycle by the ylide catalyst was established, which was confirmed by experimental mechanistic studies.
Conformationally rigid chiral bicyclic skeleton-tethered bipyridine N,N'-dioxide as organocatalyst: Asymmetric ring opening of meso-epoxides
Gnanamani, Elumalai,Someshwar, Nagamalla,Sanjeevi, Jayakumar,Ramanathan, Chinnasamy Ramaraj
supporting information, p. 2219 - 2223 (2014/07/21)
The conformationally rigid chiral bicyclic skeleton tethered bipyridine NN'-dioxide (-)-9 has been designed, synthesized and examined as an organocatalyst in the enantioselective ring opening of meso-epoxides using tetrachlorosilane (SiCl4). The catalyst (-)-9 is found to exhibit good enantioselectivity for substituted cis-stilbene epoxides; whereas, the saturated cyclic meso-epoxides display a moderate enantioselectivity. At -30 °C in chloroform, the catalyst (-)-9 with 0.5 mol % loading generated the chlorohydrins in up to 97 % yield with up to 93 % ee. The possible creation of transient axial chiral environment around hypervalent silicon species due to the presence of conformationally rigid chiral bicyclic skeleton tethered bipyridine N,N'-dioxide may be responsible for such enantioselectivity observed in the desymmetrization of meso-epoxides.
Enzymatic preparation of (1S,2R)- and (1R,2S)-stereoisomers of 2-halocycloalkanols
Kolodiazhna, Olga O.,Kolodiazhna, Anastasy O.,Kolodiazhnyi, Oleg I.
, p. 37 - 42 (2013/02/25)
The stereoisomers of cis-2-halocycloalkanols were resolved by a kinetically controlled transesterification with vinyl acetate in the presence of lipases in organic media. High enantioselectivities (ee >98%) and good isolated yields were obtained for all substrates using the appropriate lipase. Burkholderia cepacia lipase was the most efficient enzyme for the resolution of these substrates. The enantiomeric purities of the compounds were defined by derivatization with Mosher's acid and the absolute configurations were determined by chemical correlation.