Addition of Organotin Anions to α,β-Unsaturated Nitriles

Abstract

first_page settings Order Article Reprints Font Type: Arial Georgia Verdana Font Size: Aa Aa Aa Line Spacing:    Column Width:    Background: Open AccessAbstract Addition of Organotin Anions to α,β-Unsaturated Nitriles by V. Lassalle, M. T. Lockhart and A. B. Chopa * Instituto de Investigaciones en Química Orgánica, Departamento de Química e Ingeniería Química, Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina * Author to whom correspondence should be addressed. Molecules 2000, 5(3), 391-392; https://doi.org/10.3390/50300391 Published: 22 March 2000 Download Download PDF Download PDF with Cover Download XML Download Epub Versions Notes Abstract: The addition reaction of triorganotin anions to α,β-unsaturated nitriles leads to α-alkyl-β-stannylnitriles with high diastereoselectivity. IntroductionThe reaction of triphenyl- and trimethyltin anions with α,β-unsaturated ketones in acetonitrile as solvent is rather instantaneous and leads with high diastereoselectivity and in nearly quantitative yields, to β-stannylketones [1]. On the other hand, there are few reports in the literature concerned with the reaction of triorganostannyl anions with α,β-unsaturated nitriles which would lead to β-stannylnitriles through an 1,4-addition. Taking into account the application of these adducts as inter-mediates in organic synthesis [2,3] we started some studies on the reaction of triphenyl- and trimeth-yltinpotassium with compounds I, II and III, in acetonitrile (ACN) as solvent. ExperimentalTo a solution of the stannyl anion (from the reaction between an organotin hydride and potassium tert-butoxide [1]) was added a solution of the nitrile in ACN. The reaction was quenched by the addi-tion of water or an alkyl halide and then worked as usual. The adducts were purified by column chro-matography, distillation or recrystallization and characterized by 1H and 13C NMR. Results and DiscussionThe experimental results indicate that the addition reaction to α,β-unsaturated nitriles is partially inhibited by the presence of one substituent in the α- or β- positions. Thus, while acrilonitrile lead to the adduct in an 85% yield, metacrilonitrile and 2-butenonitrile gave lower yields (62% and 43% re-spectively). On the other hand, the addition is highly inhibited by the presence of α- and β-substituents in open chain olefinic systems (2,3-diphenylpropenonitrile gave a null reaction) but not in cyclic ones (1-cyanocyclohexene and 2-cyano-3,4-dihydronaphthalene gave 63% and 67% yield, respectively).The stereochemical results show that these reactions are highly diastereoselective. Thus, we only obtained pure threo isomers from open chain nitriles and cis adducts from the cyclic ones. Trapping the intermediate carbanions with different alkyl halides would allow the diastereoselective synthesis of a large number of α-alkyl-β-stannylnitriles.The diastereocontrol observed in the addition of stannyl anions to activated nitriles arises from stereoelectronic and steric effects. Acknowledgements This work was partially supported by CIC, CONICET and UNS (Argentina). The authors thank Dr. M.González Sierra (IQUIOS, Argentina) for the NMR spectra.References and NotesChopa, A.B.; Murray, A.P.; Lockhart, M.T. Evidence of single electron transfer in the dias-tereoselective synthesis of β-stannylketones. J. Organomet. Chem. 1999, 585, 35. [Google Scholar] [CrossRef] Davies, A.G. Organotin Chemistry; VCH, 1995. [Google Scholar] Murray, A.P. Thesis, 1999. Share and Cite MDPI and ACS Style Lassalle, V.; Lockhart, M.T.; Chopa, A.B. Addition of Organotin Anions to α,β-Unsaturated Nitriles. Molecules 2000, 5, 391-392. https://doi.org/10.3390/50300391 AMA Style Lassalle V, Lockhart MT, Chopa AB. Addition of Organotin Anions to α,β-Unsaturated Nitriles. Molecules. 2000; 5(3):391-392. https://doi.org/10.3390/50300391 Chicago/Turabian Style Lassalle, V., M. T. Lockhart, and A. B. Chopa. 2000. "Addition of Organotin Anions to α,β-Unsaturated Nitriles" Molecules 5, no. 3: 391-392. https://doi.org/10.3390/50300391 Find Other Styles Article Metrics No No Article Access Statistics For more information on the journal statistics, click here. Multiple requests from the same IP address are counted as one view.