796038-51-2Relevant articles and documents
A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
White, David E.,Tadross, Pamela M.,Lu, Zhe,Jacobsen, Eric N.
supporting information, p. 4165 - 4180 (2014/06/09)
The (salen)Co catalyst (4a) can be prepared as a mixture of cyclic oligomers in a short, chromatography-free synthesis from inexpensive, commercially available precursors. This catalyst displays remarkable enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen)Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminal epoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of water and carbamates; and the desymmetrization of oxetanes by intramolecular ring opening with alcohols and phenols. The favorable solubility properties of complex 4a under the catalytic conditions facilitated mechanistic studies, allowing elucidation of the basis for the beneficial effect of oligomerization. Finally, a catalyst selection guide is provided to delineate the specific advantages of oligomeric catalyst 4a relative to (salen)Co monomer 1 for each reaction class.
Highly efficient recyclable CoIII-salen complexes in the catalyzed asymmetric aminolytic kinetic resolution of aryloxy/terminal epoxides for the simultaneous production of N-protected 1,2-amino alcohols and the corresponding epoxides in high op
Kureshy, Rukhsana I.,Prathap, K. Jeya,Agrawal, Santosh,Kumar, Manish,Khan, Noor-Ul H.,Abdi, Sayed H. R.,Bajaj, Hari C.
supporting information; experimental part, p. 2863 - 2871 (2009/09/29)
Chiral CoIII-salen complexes 1-6 bearing different substituents at the 3,3′- and 5,5′-positions of the salen unit, namely H, tBu, morpholmomethyl, and piperidinomethyl, have been synthesized. These complexes were used as catalysts in an environ
Asymmetric catalytic synthesis of enantiopure N-protected 1,2-amino alcohols
Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Locatelli, Manuela,Melchiorre, Paolo,Sambri, Letizia
, p. 3973 - 3975 (2007/10/03)
(Chemical Equation Presented) The asymmetric aminolytic kinetic resolution (AKR) of racemic terminal epoxides using carbamates as the nucleophile catalyzed by (salen)CoIII complex provides a practical and straightforward method for the synthesis of both aliphatic and aromatic N-Boc- or N-Cbz-protected 1,2-amino alcohols in almost enantiomerically pure form (ee ≥ 99%). The AKR uses an easily accessible catalyst and inexpensive starting materials, and the reactions are conveniently carried out at room temperature under an air atmosphere.
