Investigation of the Reaction of 2-Bromo-1,4-dimethoxynaphthalene and 9-Bromophenanthrene with Nitriles Under Aryne-Forming Conditions
作者:Marcus Hansen、Subhash P. Khanapure、Michael Fry、Dan Swartling、Edward R. Biehl
DOI:10.1055/s-1994-25613
日期:——
The reaction of 2-bromo-1,4-dimethoxynaphthalene (1) and 9-bromophenanthrene (3) with nitriles 2 under base-mediated, aryne-forming conditions gives product distributions which depend upon the nature of the bromoarene, nitrile, base, and the reaction medium. Thus, treatment of 1 with arylacetonitriles 2a-d in the presence of LDA in THF or sodium amide in liquid ammonia supplies α-aryl-1,4-dimethoxy-2-naphthylacetonitriles 4a-d, presumably by the aryne arylation mechanism. In contrast, the reaction of 9-bromo-phenanthrene (3) and arylacetonitriles 2b-e with LDA in THF yields 10-arylmethyl-9- phenanthrenecarbonitriles 6b-e, most likely by the tandem addition-rearrangement pathway. When 3 reacts with 2a-c in the presence of sodium amide and liquid ammonia, α-aryl-9-phenanthrylacetonitriles 5a-c, rather than the rearranged nitriles 6a-c, are obtained. Both 1 and 3 react with alkylnitriles 2f-i and LDA-THF, sodium amide-liquid ammonia, or Caubere's sodamide base to afford aryne arylated nitriles (4f-i and 5f-i, respectively). An explanation in terms of the influence of reactants and solvent on the competition between the aryne arylation and tandem addition-rearrangement pathways is presented.
2-溴-1,4-二甲氧基萘(1)和9-溴菲(3)与腈2在碱介导、芳炔形成条件下反应,产物的分布取决于溴芳烃、腈、碱和反应介质的性质。因此,在LDA存在下,1与芳基乙腈2a-d在四氢呋喃中或与钠胺在液态氨中反应,推测通过芳炔芳基化机制生成α-芳基-1,4-二甲氧基-2-萘基乙腈4a-d。相反,9-溴菲(3)与芳基乙腈2b-e在LDA存在下的四氢呋喃中反应,最可能通过串联加成-重排途径生成10-芳甲基-9-菲碳腈6b-e。当3与2a-c在钠胺和液态氨存在下反应时,得到的是α-芳基-9-菲乙腈5a-c,而不是重排的腈6a-c。1和3均与烷基腈2f-i以及LDA-THF、钠胺-液态氨或Caubere的钠胺碱反应,生成芳炔芳基化腈(分别为4f-i和5f-i)。本文提出了关于反应物和溶剂对芳炔芳基化和串联加成-重排途径竞争影响的解释。