126683-86-1Relevant academic research and scientific papers
Reactions of 1- and 2-Halo and 1,2-Dichloroadamantanes with Nucleophiles by the SRN1 Mechanism
Santiago, Ana N.,Stahl, Adriana E.,Rodriguez, Gladis L.,Rossi, Roberto A.
, p. 4406 - 4411 (1997)
2-Bromoadamantane (2-BrAd) reacted in liquid ammonia under irradiation with diphenylphosphide (Ph2P-) ions whereas 2-chloroadamantane (2-ClAd) did not under the same experimental conditions. However, 2-ClAd yielded 2-(trimethylstannyl)adamantane in its photostimulated reaction with trimethylstannyl (Me3Sn-) ions. The compound 1-ClAd yielded the substitution product in a photostimulated slow reaction when the nucleophile is Ph2P- ion; the reaction occurs faster with the nucleophile Me3Sn- ion. All these reactions can be explained by the SRN1 mechanism as they did not occur in the dark and were inhibited by p-dinitrobenzene when photostimulated. In competition experiments, 1-haloadamantane showed more reactivity than 2-haloadamantane. Either with Ph2P- or Me3Sn- ions, 1-BrAd is 1.4 times more reactive than 2-BrAd while 1-ClAd is 12 times more reactive than 2-ClAd with Me3Sn- ions. In the photostimulated reaction of 1,2-dichloroadamantane (7) with Ph2P- the monosubstitution products 1-adamantyldiphenylphosphine (64%) and 2-adamantyldiphenylphosphine (15%) were formed, isolated as the oxides. From these results, it appears that when 7 receives an electron, the 1-position fragments ca. four times faster than the 2-position. The disubstitution product was not formed with Ph2P- ions, but when 7 reacted with a nucleophile having less steric bulk such as a Me3Sn- ion, the 2-chloro-1-(trimethylstannyl)-adamantane and the disubstitution product 1,2-bis(trimethylstannyl)adamantane were formed. The formation of these products is explained in terms of the different rates of the electron transfer reactions of the radical anion intermediates.
