- The search for an easily-prepared sparteine surrogate
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(?)-Sparteine has proven itself to be a highly efficient and versatile ligand. However, in recent years it has become difficult to source. In addition the (+)-enantiomer is also not readily available. Here we report a suite of chiral diamines as potential sparteine surrogates. Chiral trans-1,2-diaminocyclohexane is commercially available in both enantiomeric forms and the parent structure can be easily modified. New (and known) chiral diamines have been tested in the asymmetric silylation of N-Boc pyrrolidine, N-Boc piperidine, the α-alkylation of dimethylhydrazones and in the rearrangement of meso-epoxides. While none match the selectivity of the highly evolved natural product, there is certainly potential for this class of diamine ligands to perform in a diverse set of asymmetric transformations.
- Foley, Vera M.,Cano, Rafael,McGlacken, Gerard P.
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p. 1160 - 1167
(2016/11/04)
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- Organocatalytic Knoevenagel condensation by chiral: C 2-symmetric tertiary diamines
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The efficient Knoevenagel condensation catalyzed by (1S,2S)-1,2-diaminocyclohexane derivatives is presented and investigated. Various aliphatic aldehydes undergo condensation with active methylene compounds to yield the corresponding products in high yields. α-Branched aldehydes were found to be efficiently converted to the corresponding enantiomerically enriched products by using these chiral tertiary diamine catalysts.
- Gu, Xiaoyu,Tang, Yan,Zhang, Xiang,Luo, Zinbin,Lu, Hongfei
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supporting information
p. 6580 - 6583
(2016/08/09)
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- Novel chiral bisformamide-promoted asymmetric allylation of benzaldehyde with allyltrichlorosilane
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Novel chiral bisformamides have been prepared from (R,R)-1,2- cyclohexanediamine and utilized as Lewis bases in the asymmetric allylation of benzaldehyde with allyltrichlorosilane. The reaction in the presence of Lewis base 1i gave an 83:17 enantiomeric r
- Ishimaru, Kaori,Ono, Kaori,Tanimura, Yuya,Kojima, Takakazu
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p. 3627 - 3634
(2011/10/09)
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- Supramolecular-directed chiral induction in biaryl derivatives
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(Chemical Equation Presented) A thermodynamically controlled resolution has allowed for the generation of diastereomerically enriched complexes, by chirality transfer from an enantiopure building block to a dynamically racemic biaryl derivative. A switcha
- Etxebarria,Degenbeck,Felten,Serres,Nieto,Vidal-Ferran
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supporting information; experimental part
p. 8794 - 8797
(2010/03/04)
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