Synergic asymmetric organocatalysis (SAOc) of Cinchona alkaloids and secondary amines in the synthesis of bicyclo[2.2.2]octan-2-ones.
نویسندگان
چکیده
A synergistic effect between chiral secondary and tertiary amines gives access to bicyclo[2.2.2]octan-2-ones with up to 90% ee and >10 : 1 dr.
منابع مشابه
N-(2-Bromobenzyl)cinchoninium bromide
The title compound {systematic name: 1-(2-bromo-benz-yl)-5-ethenyl-2-[hy-droxy(quinolin-4-yl)meth-yl]-1-aza-bicyclo-[2.2.2]octan-1-ium bromide}, C(26)H(28)BrN(2)O(+)·Br(-), is a chiral quater-nary ammonium salt of one of the Cinchona alkaloids. The planes of the quinoline and of the bromo-benzyl substituent are inclined to one another by 9.11 (9)°. A weak intra-molecular C-H⋯O hydrogen bond occ...
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Benzylidene acetone reacts with thiocyanates derived from secondary amines in a one-pot reaction to give 4-aminobicyclo[2.2.2]octan-2-ones. The reaction mixture was investigated for the presence of possible intermediates using GC-MS. These intermediates - diketones and enamines - were prepared and exposed to the same reaction conditions to examine the reaction mechanism. The reaction of ethyl s...
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Disclosed herein is a stereoselective method for the synthesis of 2,3-furan fused carbocycles bearing adjacent quaternary and tertiary carbon stereocenters. The chemistry is based on an asymmetric addition of β-ketoesters to 2-(1-alkynyl)-2-alkene-1-ones catalysed by natural cinchona alkaloids followed by a silver-catalysed intramolecular cycloisomerisation. By exploiting the distinct catalysis...
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The combination of cinchona-alkaloid-derived primary amine and Au(I) -phosphine catalysts allowed the selective C-H functionalization of two adjacent carbon atoms of pyrroles under mild reaction conditions. This sequential dual activation provides seven-membered-ring-annulated pyrrole derivatives in excellent yields and enantioselectivities.
متن کاملDiastereodivergent organocatalysis for the asymmetric synthesis of chiral annulated furans† †Electronic supplementary information (ESI) available: Complete experimental procedures and full compound characterisation, including HPLC traces and NMR spectra (PDF). CCDC 1046068 and 1046069. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc01052g
Disclosed herein is a stereoselective method for the synthesis of 2,3-furan fused carbocycles bearing adjacent quaternary and tertiary carbon stereocenters. The chemistry is based on an asymmetric addition of b-ketoesters to 2-(1-alkynyl)-2-alkene-1-ones catalysed by natural cinchona alkaloids followed by a silver-catalysed intramolecular cycloisomerisation. By exploiting the distinct catalysis...
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ورودعنوان ژورنال:
- Chemical communications
دوره 5 شماره
صفحات -
تاریخ انتشار 2009