Photochemical Strategy for Carbon Isotope Exchange with CO2
A photocatalytic approach for carbon isotope exchange is reported. Utilizing [13C]CO2 and [14C]CO2 as primary C1 sources, this protocol allows the insertion of the desired carbon isotope into phenyl acetic acids without the need for structural modifications or prefunctionalization in one single step. The exceptionally mild conditions required for this traceless transformation are in stark contrast with those for previous methods requiring the use of harsh thermal conditions.
Fast Carbon Isotope Exchange of Carboxylic Acids Enabled by Organic Photoredox Catalysis
Carbazole/cyanobenzene photocatalysts promote the direct isotopic carboxylate exchange of C(sp3) acids with labeled CO2. Substrates that are not compatible with transition-metal-catalyzed degradation-reconstruction approaches or prone to thermally induced reversible decarboxylation undergo isotopic incorporation at room temperature in short reaction times. The radiolabeling of drug molecules and precursors with [11C]CO2 is demonstrated.
Kong, Duanyang,Munch, Maxime,Qiqige, Qiqige,Cooze, Christopher J. C.,Rotstein, Benjamin H.,Lundgren, Rylan J.
supporting information
p. 2200 - 2206
(2021/02/16)
A PROCESS FOR THE SYNTHESIS OF CARBON LABELED ORGANIC COMPOUNDS
The present invention relates to a process for the synthesis of a carbon labeled organic compound containing a carbon labeled carboxyl group. The present invention also concerns the use of carbon labeled organic compounds containing a carbon labeled carbo
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Page/Page column 50; 55
(2019/10/29)
Acetolysis of 2-Aryl-1-methylpropyl Systems: Mechanism of the Formation of the Retained Product without Neighbouring Group Participation
threo-2--1-(13C)methylpropyl p-bromobenzenesulphonate (threo-(13C)1-OBs) has been solvolyzed in acetic acid to give rise to the retained threo-1-OAc which contains a small amount of threo-(13C)1-OAc accompanying no 13C-scrambling.At 75percent conversion, the isomerized erythro-1-OBs has been obtained along with the unchanged threo-1-OBs.Also, the erythro-1-OTs has been found at 50percent conversion in the presence of NaOTs.These stereochemical results indicate strongly that the acetate with the retained configuration accompanying no 13C-scrambling is formed via isomerization of the substrate by inversive anion exchange and a successive ks pathway with configurational inversion.Such a retained product was not detected in the acetolysis of threo-1-methyl-2-phenylpropyltoluene-p-sulphonate with no electron withdrawing substituent.