Aryl ketones were reduced to the corresponding alcohols with excellent enantioselectivity by trichlorosilane in the presence of a catalytic amount of N-formyl-α'-(2,4,6-triethylphenyl)-L-proline as an activator.
Y. Matsumura, K. Ogura, Y. Kouchi, F. Iwasaki, O. Onomura, Org. Lett., 2006, 8, 3789-3792.
Asymmetric reduction of ketimines with trichlorosilane can be catalyzed by N-methylvaline-derived Lewis-basic formamides with high enantioselectivity and low catalyst loading at room temperature in toluene. Appending a fluorous tag to the catalyst simplifies the isolation procedure and allows the catalyst to be recycled.
A. V. Malkov, M. Figlus, S. Stončius, P. Kočovský, J. Org. Chem., 2007, 72, 1315-1325.
L-Piperazine-2-carboxylic acid derived N-formamides are highly enantioselective Lewis basic catalysts for the hydrosilylation of imines with trichlorosilane. High isolated yields and enantioselectivities were obtained for a broad range of substrates, including aromatic and aliphatic ketimines.
Z. Wang, M. Cheng, P. Wu, S. Wei, J. Sun, Org. Lett., 2006, 8, 3045-3048.
L-Pipecolinic acid derived formamides are highly efficient and enantioselective Lewis basic organocatalysts for the mild reduction of various N-aryl imines with trichlorosilane.
Z. Wang, X. Ye, S. Wei, P. Wu, A. Zhang, J. Sun, Org. Lett., 2006, 8, 999-1001.
Lewis base promoted direct reductive hydrazination enables a straightforward and facile synthesis of 1,1-disubstituted hydrazines with very good yields. Under the catalysis of hexamethylphosphoramide (HMPA) and N,N-dimethylacetamide (DMAc), respectively, various ketones and aldehydes reacted with phenylhdrazines.
T. Wang, X. Di, C. Wang, L. Zhou, J. Sun, Org. Lett., 2016, 18, 1900-1903.
The combination HSiCl3 and a tertiary amine enables a mild, metal-free reduction of both aromatic and aliphatic nitro groups to amines. The reaction is of wide general applicability and tolerates many functional groups.
M. Orlandi, F. Tosi, M. Bonsignore, M. Benaglia, Org. Lett., 2015, 17, 3941-3943.
A chiral bisphosphine dioxide catalyzes an asymmetric conjugate reduction of acyclic β,β-disubstituted α,β-unsaturated ketones with trichlorosilane to provide saturated ketones with high enantioselectivities. Due to concomitant E/Z-isomerizations of enone substrates, reduction products with the same absolute configurations are obtained from either (E)- or (Z)-enones.
M. Sugiura, Y. Ashikari, Y. Takahashi, K. Yamaguchi, S. Kotani, M. Nakajima, J. Org. Chem., 2019, 84, 11458-11473.
A triphenylphosphine oxide catalyzed reductive halogenation of an α,β-unsaturated ketone with trichlorosilane as the reducing reagent and an N-halosuccinimide as the electrophilic halogen source enables a selective synthesis of unsymmetrical α-haloketones.
Z. Lao, H. Zhang, P. H. Toy, Org. Lett., 2019, 21, 8149-8152.
In a triphenylphosphine oxide-catalyzed reduction of conjugated polyunsaturated ketones using trichlorosilane as reducing reagent, the α,β-C=C double bond was selectively reduced while all other reducible functional groups remained unchanged. Additionally, a tandem one-pot Wittig/conjugate-reduction reaction sequence provides γ,δ-unsaturated ketones from simple building blocks.
X. Xia, Z. Lao, P. H. Toy, Synlett, 2019, 30, 1100-1104.