- Chiral hetero- and carbocyclic compounds from the asymmetric hydrogenation of cyclic alkenes
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Several types of chiral hetero- and carbocyclic compounds have been synthesized by using the asymmetric hydrogenation of cyclic alkenes. N,P-Ligated iridium catalysts reduced six-membered cyclic alkenes with various substituents and heterofunctionality in good to excellent enantioselectivity, whereas the reduction of five-membered cyclic alkenes was generally less selective, giving modest enantiomeric excesses. The stereoselectivity of the hydrogenation depended more strongly on the substrate structure for the five- rather than the six-membered cyclic alkenes. The major enantiomer formed in the reduction of six-membered alkenes could be predicted from a selectivity model and isomeric alkenes had complementary enantioselectivity, giving opposite optical isomers upon hydrogenation. The utility of the reaction was demonstrated by using it as a key step in the preparation of chiral 1,3-cis-cyclohexane carboxylates. Copyright
- Verendel, J. Johan,Li, Jia-Qi,Quan, Xu,Peters, Byron,Zhou, Taigang,Gautun, Odd R.,Govender, Thavendran,Andersson, Pher G.
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supporting information; experimental part
p. 6507 - 6513
(2012/06/29)
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- A modular rearrangement approach toward medicinally relevant phosphinic structures
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An unprecedented coupling of a P - C and a C - C bond-forming event In a practical operation was developed to access medicinally relevant phosphinic structures. The strategy relies on an Ireland-Claisen rearrangement triggered by the phospha-Michael addition of silyl phosphonltes to allyl acrylates. This protocol was extended to a more versatile three-component variant that utilizes phosphinic acids, acryloyl chlorides, and allylic alcohols as starting materials.
- Rogakos, Vassilis,Georgiadis, Dimitris,Dive, Vincent,Yiotakis, Athanaslos
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supporting information; experimental part
p. 4696 - 4699
(2009/12/08)
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- Selective enzymatic epoxidation of dienes: Generation of functional enantiomerically enriched diene monoepoxy monomers
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Enantiomerically enriched diene monoepoxides were selectively synthesized using oxidases from Pseudomonas sp. and chloroperoxidase from Caldariomyces fumago. These monoepoxides are useful monomers for generating functional chiral polymeric materials.
- Hu, Shanghui,Gupta, Pankaj,Prasad, Ashok K,Gross, Richard A,Parmar, Virinder S
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p. 6763 - 6766
(2007/10/03)
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