Categories: C-Cl Bond Formation >
Synthesis of α-chloroketones and α-chloroaldehydes
Recent Literature
The use of enamine catalysis has provided a new organocatalytic strategy for
the enantioselective chlorination of aldehydes to generate α-chloro aldehydes,
an important chiral synthon for chemical and medicinal agent synthesis.
M. P. Brochu, S. P. Brown, D. W. C. MacMillan, J. Am. Chem. Soc.,
2004,
126, 4108-4109.
A direct organocatalytic enantioselective α-chlorination of aldehydes
proceeds for a series of different aldehydes with NCS as the chlorine source
using easily available catalysts such as L-proline amide and (2R,5R)-diphenylpyrrolidine.
The α-chloro aldehydes are obtained in very good yield and high
enantioselectivity.
N. Halland, A. Braunton, S. Bachmann, M. Marigo, K. A. Jorgensen, J. Am. Chem. Soc.,
2004,
126, 4790-4791.
Catalytic enantioselective fluorination and chlorination reactions of carbonyl
compounds were achieved with high enantioselectivity by the use of a dbfox-NiII
complex.
N. Shibata, J. Kohno, K. Takai, T. Ishimaru, S. Nakamura, T. Toru, S.
Kanemasa, Angew. Chem. Int. Ed., 2005,
44, 4204-4207.
The regio- and stereoselective aminochlorination of α,β-unsaturated ketones
with N,N-dichloro-p-toluenesulfonamide (4-TsNCl2) and
CuOTf as catalyst provides an easy access to
vicinal haloamino ketones, with excellent regioselectivity and good yields.
Aromatic and aliphatic enones give opposite regioselectivity.
D. Chen, C. Timmons, S. Chao, G. Li, Eur. J. Org. Chem., 2004,
3097-3101.
Poly{[4-(hydroxy)(tosyloxy)iodo]styrene} was efficient in the halotosyloxylation
reaction of alkynes with iodine or NBS or NCS. The polymer reagent could be
regenerated and reused.
J.-M. Chen, X. Huang, Synthesis, 2004,
1557-1558.
