793-40-8Relevant academic research and scientific papers
Nucleophilic substitution induced by electron transfer at the bridgehead of polycyclic alkanes: Competition between polar and radical pathways
Adcock,Clark,Trout
, p. 3362 - 3371 (2007/10/03)
A series of 2,5(or 1,4)-dihaloadamantanes (4 and 5, X = Y = halogens) and 9,10-dihalotriptycenes (7, X = Y = halogens) as well as two 5-halo (X) adamantan-2-ones (6, Y = O,X = Br and I) have been treated with Me3SnLi in THF in the absence and presence of tert-butylamine (TBA) and dicyclohexylphosphine (DCHP). The product distributions of these reactions have been established by 13C and 119Sn NMR spectroscopy, vapor-phase chromatographic analyses, and GC/MS. The former compounds (4 and 5) appear to react exclusively by a free-radical chain process (SRN1 mechanism) to yield tin substitution products. By contrast, the triptycenes react predominantly by a polar mechanism initiated by the formation of a carbanion. In the case of the halo ketones (6, Y = O,X = Br and I), a mechanistic divergence of the reaction was unexpectedly encountered. Whereas the bromo ketone provides the substitution product (6, Y = O,X = SnMe3) in good yield (ca. 75%), apparently by a radical pathway, the iodo ketone yields a fragmentation product (ca. 95% yield) by a polar mechanism. This mechanistic switch highlights the importance of the electronegativity of the leaving group as well as substituent-induced electron delocalization as molecular factors governing the competition between radical and polar pathways.
Photochemical Chlorodecarboxylation via an Electron Transfer Mechanism
Okada, Keiji,Okamoto, Kazushige,Oda, Masaji
, p. 1636 - 1637 (2007/10/02)
A new method of chlorodecarboxylation of carboxylic acids via N-acyloxyphthalimides is developed; the reaction proceeds upon irradiation of N-acyloxyphthalimides in the presence of 1,4-diazabicyclooctane in ButOH-CCl4-H2O (53:42:5 v/v) in moderate to high yields.
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.
