18747-95-0Relevant academic research and scientific papers
Photoredox-Catalyzed Cα-H Cyanation of Unactivated Secondary and Tertiary Aliphatic Amines: Late-Stage Functionalization and Mechanistic Studies
Yilmaz, Ozgur,Oderinde, Martins S.,Emmert, Marion H.
, p. 11089 - 11100 (2018/09/12)
This paper describes the development and mechanistic studies of a general, high-yielding amine Cα-H cyanation protocol via photoredox catalysis. Inexpensive NaCN is employed as the cyanide source and air is the external oxidant, resulting in mild and highly functional group tolerant conditions. Notably, efficient Cα-H cyanations of secondary and tertiary aliphatic amines and of complex, biologically active compounds (drugs) can be performed using the established methodology. Mechanistic studies suggest that the carboxylic acid additive has three effects: formation of a stabilizing hemiaminal intermediate, prevention of catalyst decomposition by protonating the substrate, and modulation of fluorescence quenching of the photoexcited catalyst species.
A metal-free direct C (sp3)-H cyanation reaction with cyanobenziodoxolones
Sun, Ming-Xue,Wang, Yao-Feng,Xu, Bao-Hua,Ma, Xin-Qi,Zhang, Suo-Jiang
supporting information, p. 1971 - 1975 (2018/03/23)
A metal-free protocol of direct C(sp3)-H cyanation with cyanobenziodoxolones functioning as both cyanating reagents and oxidants was developed. Unactivated substrates, such as alkanes, ethers and tertiary amines, were thereby transformed to the corresponding nitriles in moderate to high yields. Mechanistic studies indicated that the cyanation proceeded with two potential pathways, which is highly dependent on the substrates: (1) a free radical case for alkanes and ethers and (2) an oxidative case for tertiary amines.
An approach to some spiro oxindole alkaloids through cycloaddition reactions of 3-methylideneindolin-2-one
Bell, Stephanie E. V.,Brown, Roger F.C.,Eastwood, Frank W.,Horvath, Julianna M.
, p. 183 - 190 (2007/10/03)
3-Methylideneindolin-2-one (3-methylideneoxindole) (1) was prepared in 60-89% yield by flash vacuum pyrolysis of the acetate or methyl carbonate of 3-hydroxy-3-methylindolin-2-one, and was fully characterized, but application of the same procedure to 3-hydroxy-5-methoxyindolin-2-one did not give useful yields. Cycloaddition reactions of CH2=+NR-CH2- and of the related ylide (25) (from 1-(trimethylsilylmethyl)piperidine-2-carbonitrile and AgF) to 3-methylideneindolin-2-one (1) gave 4-20% yields of spiro oxindoles, but yields were markedly below those achieved in cycloadditions to the more electrophilic N-phenylmaleimide (70-79%). Attempted alkylation of weakly basic secondary amines, e.g. piperidine-2-carbonitrile, with Me3SiCH2Cl in dimethyl sulfoxide/K2CO3 gave only carbamates Me3SiCH2OOCNR2. CSIRO 2000.
REGIOSPECIFIC FUNCTIONALISATION OF CARBON ATOMS α TO HETEROCYCLIC NITROGEN
Koskinen, Ari,Lounasmaa, Mauri
, p. 1627 - 1634 (2007/10/02)
Previously, methods have been devised to functionalise the two endocyclic C atoms α to the piperidine N.In the present study we show that a nitrile substituent can be introduced also to the exocyclic α-C, making the centre either nucleo- or electrophilic in subsequent transformations.NMR studies have been used to gain knowledge of the mechanistic aspects leading to the observed regiospecificity.The generality of the method, along with the ease of operation, high yields and regiospecificity, make it highly versatile for synthetic purposes.
