LDA (Lithium Diisopropylamide) Mediated Reactions of 1-Naphthalynes with Lithiated Acetonitriles and 1,4-Dipolar Nucleophilic Anions
作者:Edward R. Biehl、A. Rakeeb Deshmukh、Mahesh Dutt
DOI:10.1055/s-1993-25963
日期:——
3-Bromo-2-methoxy-(5) and 3-bromo-2-methoxy-6-methylnaphthalene (6) yield 1-naphthalyne intermediates which react with various α-lithiated nitriles 10 to afford both rearranged 1-arylmethyl- or 1-hetarylmethyl-3-methoxynaphthalene-2-carbonitriles 11 and 12, respectively, and α-naphthylated aryl- or hetarylacetonitriles 13 and 14, respectively. Product distributions 11:13 favoring rearranged nitriles (65:35-90:10) were obtained from LDA-mediated reactions of 5 with arylacetonitriles 9a, b and thiopheneaceto-nitriles 9c, d. Similar treatment of 6 with 9a-d gave product distributions 12:14 heavily in favor of rearranged nitriles (> 90:10) presumably due to the ability of the additional 7-methyl group to increase the rate of cyclization of the initial aryne-nitrile anion adduct, the crucial step in the rearrangement pathway. However treatment of either 5 or 6 with α-lithiated pyridylacetonitriles 9e, f or 2-benzimidazolylacetonitrile (9g) gave product distributions 11:13 or 12:14, respectively, heavily in favor of α-naphthylated acetonitriles (30: 70 > 10: 90). Additionally, several precursors to methoxy-substituted 1-naphthalynes 5,19 and 20 were found to undergo cycloaddition with the dipolar nucleophilic precursors 3-cyanophthalide (17) and α-cyano-o-tolunitrile (21) to give angularly substituted benz[α]anthracene derivatives 18, 22.
3-溴-2-甲氧基-(5)和3-溴-2-甲氧基-6-甲基萘(6)生成的1-萘基中间体与各种α-锂化腈10反应,分别产生重排的1-芳基甲基或1-杂环芳基甲基-3-甲氧基萘-2-碳腈11和12,以及α-萘基化的芳基或杂环乙腈13和14。从LDA介导的5与芳基乙腈9a、b以及噻吩乙腈9c、d的反应中,获得了重排腈的产物分布11:13,更倾向于重排腈(65:35-90:10)。对6与9a-d进行类似处理,得到的产物分布12:14严重偏向重排腈(> 90:10),这可能是由于额外的7-甲基基团能够增加初始芳烯-腈阴离子加合物的环化速率,这是重排途径中的关键步骤。然而,5或6与α-锂化的吡啶乙腈9e、f或2-苯并咪唑基乙腈(9g)的反应,分别得到的产物分布11:13或12:14,则严重偏向α-萘基化的乙腈(30:70 > 10:90)。此外,几个甲氧基取代的1-萘基前驱体5、19和20被发现与双极性亲核前驱体3-氰基邻苯二甲酸酯(17)和α-氰基-o-甲苯腈(21)发生环加成,生成角度取代的苯[α]蒽衍生物18、22。