2733-29-1Relevant articles and documents
Rhodium-catalyzed regio- and stereoselective oxyamination of dienes via tandem aziridination/ring-opening of dienyl carbamates
Guasch, Joan,Díaz, Yolanda,Matheu, M. Isabel,Castillón, Sergio
supporting information, p. 7344 - 7347 (2014/07/07)
The reaction of dienyl carbamates with PhI(OR)2 in the presence of rhodium catalysts affords vinyl aziridines which are in situ regio- and stereoselectively opened to afford oxyamination products resulting from a selective SN2 (Rh2(OAc)4/PhI(OPiv)2) or SN2′ (Rh2(OPiv)4/PhI(OAc) 2) opening. The scope and limitations of this tandem process are described.
Efficient silver-catalyzed regio- and stereospecific aziridination of dienes
Llaveria, Josep,Beltran, Alvaro,Diaz-Requejo, M. Mar,Perez, Pedro J.,Matheu, M. Isabel,Castillon, Sergio
supporting information; experimental part, p. 7092 - 7095 (2010/11/05)
Nitrene transfer: Unsymmetric dienes bearing a terminal hydroxy group can be regio- and stereospecifically converted into vinylaziridines upon nitrene transfer from PhINTs using a silver-based catalyst. Stoichiometric mixtures of dienes and PhINTs were employed at low catalyst loadings (0.5□%; see scheme). The method has been applied to the synthesis of (±)-sphingosine and gave good yields in a three-step procedure. Ts=4-toluenesulfonyl.
Lipase-catalyzed enantiomeric resolution of ceramides 1
Bakke, Mikio,Takizawa, Masahiro,Sugai, Takeshi,Ohta, Hiromichi,Herold
, p. 6929 - 6938 (2007/10/03)
Lipase-catalyzed enantiomeric kinetic resolution of ceramides related to C16-sphinganine and C18-sphingenine is described. Two hydroxy groups in readily available racemic N-stearoyl-erythroC16-sphinganine were acetylated, and several kinds of lipases were screened for the hydrolysis of this substrate. Among them, a Burkholderia cepacia lipase (SC lipase A, Sumitomo Chemical Co., Ltd.) showed the highest reactivity and enantioselectivity. The rate of hydrolysis and selectivity were greatly affected by some additives. Especially, the combined use of a detergent, Triton X-100, and the solid support, Florisil, for immobilization showed the highest enantioselectivity (E = ca. 170), although the reaction rate turned low. Introduction of a double bond into the substrate (N-stearoyl-erythro-Cis-sphingenine) also retarded the hydrolysis. By utilizing the preferential hydrolysis of the acetate on the primary hydroxy group, another advantageous feature of this enzyme-catalyzed reaction, the resulting product could directly be used as the glycosyl acceptor for cerebroside synthesis.