1276992-88-1Relevant articles and documents
Chemo- and regioselective catalytic reduction of N-heterocycles by silane
Lee, Sun-Hwa,Gutsulyak, Dmitry V.,Nikonov, Georgii I.
supporting information, p. 4457 - 4464 (2013/09/23)
The ruthenium complex [Cp(iPr3P)Ru(NCCH3) 2]+ (1) catalyzes the regioselective hydrosilylation of pyridines to 1,4-dihydropyridines. Substitution in the 3- and 5-positions is tolerated, whereas pyridines with substituents in the 2-, 4-, and 6-positions are not reduced. Reduction of functionalized pyridines having keto and ester substituents results in a mixture of products. N-Silyl-1,4-dihydropyridine reacts with ketones and aldehydes to give products of N-Si addition across the C=O bond. Hydrosilylation of pyridine in acetone results quantitatively in the addition product PhMe2SiO-CMe2-NC5H 6, which decomposes in hexane to give the parent dihydropyridine HNC5H6. The phenanthroline complex [Cp(phen)Ru(NCCH 3)2]+ (10) catalyzes regioselective 1,4-reduction of phenanthroline by a 3-4-fold excess of silane/water or silane/alcohol mixtures. The Cp* analogue [Cp*(ph n)Ru(NCCH 3)2]+ (9) catalyzes 1,4-regioselective monohydrosilylation of phenanthroline, quinoline, acridine, and 1,3,5-triazine and the 1,2-reduction of isoquinoline. In contrast, 2-substituted phenanthroline, pyrazine, 2-ethylpyridine, 2,6-lutidine, 2,4-lutidine, and pyrimidine are not reduced under these conditions by either of the catalysts studied.
