29542-62-9Relevant articles and documents
Thermolysis of Highly Congested Tri-tert-alkylmethanes. Rearrangement of a 3-Noradamantylmethyl Radical
Lomas, John S.
, p. 519 - 528 (2007/10/02)
Activation energies for C-Ad fission in the thermolysis of di-1-adamantyl-tert-alkylmethanes and 1-adamantyl-di-1-bicyclooctylmethane, AdR1R2CH, in toluene are best correlated with the strain energy difference (MMP2 force field) between the methane and the corresponding radical, R1R2C radical H; difficulties were encountered in the application of MM3 to certain of these trialkylmethanes.Normally, the major thermolysis product is the di-tert-alkylmethane, R1R2CH2, but when a 3-noradamantly group is present (1d) the initially formed radical ring opens to give 1,2'-biadamantyl in amounts which depend on the temperature and the solvent (normal or octadeuteriated).This rearrangement is readily explained by MMP2 calculations.Since the cross-product yield is low (less than 3percent, even in deuteriated solvent at the highest temperature) the thermodynamic parameters for the hydrogen transfer and ring opening reactions of the 1-adamantyl-3-noradamantylmethyl radical can be compared directly.Both the activation enthalpy and entropy are much greater for ring opening than for hydrogen abstraction from the solvent.Isotope effects on hydrogen abstraction are high and satisfy certain criteria for tunnelling, as do data on the analogous reaction of Ad2C radical H.A more sophisticated treatment of the product composition for 1d thermolysis, using kinetic simulation, leads to essentially the same conclusions as the simpler treatment.
High-Yield Direct Synthesis of a New Class of Tertiary Organolithium Derivatives of Polycyclic Hydrocarbons
Molle, G.,Bauer, P.,Dubois, J. E.
, p. 2975 - 2981 (2007/10/02)
For the first time, 1- and 2-adamantyllithium, 1-diamantyllithium, 3,5,7-trimethyl-1-adamantyllithium, 1-twistyllithium, 3-methyl-7-noradamantyllithium, 1-triptycyllithium, and 3-homoadamantyllithium have been directly synthesized from the reaction of an organic halide and lithium metal.By use of certain experimental parameters, the phenomena at the metal-solution interface are controlled, thereby resulting in exceptionally high yields of this new class of organometallic compounds (>75percent, except in the case of 3-homoadamantyllithium).Competition between formation of the organometallic compound and formation of solvent-attack byproducts is determined by the degree of adsorption of the transient species (anion radical RX-. or radical pair R..Li) generated at the metal surface during attack by the halogenated derivative.