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11.
Delphine Didier 《Tetrahedron》2007,63(18):3864-3869
In this paper, we report the synthesis of amino and aminomethyl derivatives of Tröger's base (±)-1 and (±)-2. The key steps in the synthesis of (±)-1 and (±)-2 are Pd-catalyzed amination and cyanation, respectively, of the easily accessible dihalo derivatives (±)-3. These compounds are important intermediates in the synthesis of new ligands and building blocks for H-bonded supramolecular architectures. 相似文献
12.
A new self-assembled catalyst based on titanium complex has been developed for the effective enantioselective cyano-ethoxycarbonylation of aldehydes. The self-assembled catalyst was readily prepared from (R)-3,3′-bis((methyl((S)-1-phenylethyl)amino)methyl)-1,1′-binaphthyl-2,2′-diol (1h), N-((1S,2R)-2-hydroxy-1,2-diphenylethyl)acetamide (2b), and tetraisopropyl titanate (Ti(OiPr)4). A variety of aromatic aldehydes, aliphatic aldehydes, and α,β-unsaturated aldehydes were found to be suitable substrates in the presence of the self-assembled titanium catalyst (5 mol % 1h, 5 mol % 2b, and 5 mol % Ti(OiPr)4). The desired cyanohydrin ethyl carbonates were afforded with high isolated yields (up to 95%) and moderate to good enantioselectivities (up to 92% ee) under mild conditions (at −15 °C). A possible catalytic cycle based on the experimental observation was proposed. 相似文献
13.
María Torrado 《Tetrahedron letters》2007,48(2):323-326
A series of substituted tetralones as intermediates of CNS agents has been synthesized via Pd-catalyzed coupling reactions of 3-(methoxycarbonyl)-1,2,3,4-tetrahydro-1-oxonaphthalen-6-yl trifluoromethanesulfonate (5) with a variety of organometallic reagents. 相似文献
14.
Qing Liu Shuchen Yu Liangzhen Hu Muhamad Ijaz Hussain Xiaohui Zhang Yan Xiong 《Tetrahedron》2018,74(50):7209-7217
The cross-dehydrogenative coupling strategy for metal-free phosphonation and cyanation of secondary N-alkyl anilines has been developed firstly under mild reaction conditions. Based on detailed optimization of reaction conditions, the substrate generality of N-alkyl anilines and various hydrogen phosphonates has been investigated, and a series of versatile α-aminophosphonates and α-aminonitriles were therefore furnished in good to excellent yields. A plausible collective reaction mechanism through dehydrogenation to imine formation, then to respective α-aminophosphonates and α-aminonitriles was proposed. 相似文献
15.
The diastereoselective cyanation of α‐keto amides using trimethylsilyl cyanide in the presence of a Lewis acid is described. The corresponding O‐acetylated cyanohydrins are obtained in good to high levels of stereoselectivities. The predominance of products with the S absolute configuration at the newly generated stereogenic center was deduced from single crystal X‐ray analysis. 13C NMR data suggest that a preferential s‐cis conformation was formed by the chelation of a Lewis acid to the dicarbonyl oxygen atoms. 相似文献
16.
Visible-light-induced aerobic oxidative cyanation of aza-Baylis–Hillman (aza-BH) adducts providing valuable allylic cyanides in good to excellent yields has been developed. The protocol involves in situ formation of 4π conjugated iminium ion intermediates, which undergo cyanation at the γ-position to afford Michael type adducts. This is the first example of visible-light-induced catalytic functionalization of aza-BH adducts using air (O2) as an economical and ecosustainable oxidant and TMSCN as a convenient and readily available cyanide source. 相似文献
17.
S. H. R. Abdi R. I. Kureshy N. H. Khan V. J. Mayani H. C. Bajaj 《Catalysis Surveys from Asia》2009,13(2):104-131
This review is based on dimeric and polymeric chiral Schiff base metal complexes and chiral BINOL supported metal complexes
as potential recyclable catalysts for kinetic resolution of racemic and meso epoxide and asymmetric C–C bond formation reactions e.g., asymmetric addition of diethylzinc to aldehydes, enantioselective
addition of phenylacetylene to aldehydes, asymmetric nitro-Aldol reactions and asymmetric cyanation reaction. 相似文献
18.
Nanostructured hybrid silica bearing pyridine binding sites was prepared in a template assisted hydrolysis-polycondensation of tetraethylorthosilicate (TEOS) and the ionic precursor N,N-dimethyl-pyridin-4-yl-(3-triethoxysilyl-propyl)-ammonium iodide using N-dodecyl-N′-methyl-imidazolium bromide as structure directing agent. After treatment with palladium acetate, the material appeared as a versatile heterogeneous catalyst for Heck, Sonogashira, and cyanation reactions. In Heck and Sonogashira cross-coupling reactions, unchanged catalytic activity was observed in at least five reaction cycles. 相似文献
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20.
A facile synthesis for cyanochlorin related to chlorophyll from a formyl-substituted chlorin, by the oxidation ofmethyl (pyro)pheophorbide-α, was accomplished. These readily available chlorin aldehydes were assembled together with hydroxylamine hydrochloride in a tandem process to produce the corresponding chlorin nitriles inmoderate to good yields. The formation of chlorin nitrile was discussed and a possible mechanism for the corresponding cyanation reaction was tentatively proposed. 相似文献