13643-06-6Relevant academic research and scientific papers
Attempts To Trap Radicals Formed in Solution by a Magnesium Surface
Walborsky, H. M.,Topolski, M.,Hamdouchi, C.,Pankowski, J.
, p. 6188 - 6191 (1992)
The synthesis of 2,2'-azo-2-methyl-6-heptene (1) is discribed.Photolytic decomposition of 1 in ether gave rise to the 1,1-dimethyl-5-hexenyl radical clock (2) which yielded 1,1,2-trimethylcyclopentane (3), 6-methyl-1-heptene (4), and 2-methyl-1,6-heptadiene (5) in the ratio of 1:0.72:0.56, respectively.The ratio did not change appreciably when a well-stirred mixture of 1 and 5 equiv of magnesium powder was photolyzed.Moreover, the solution gave a negative test (2,2'-biquinoline) for the presence of Grignard reagent.Thus, it has been esperimentally demonstrated that the radicals formed in solution do not react with a magnesium surface to form Grignard reagents.
Conversion of non-conjugated dienes into conjugated diene-zirconocenes via multipositional regioisomerization
Maye, John P.,Negishi, Ei-Ichi
, p. 3359 - 3362 (1993)
The reaction of n-Bu2ZrCp2 with non-conjugated dienes (1) containing a mono- or 1,2-disubstituted alkene at one end and a 1,1-di- or trisubstituted alkene at the other gives conjugated diene-zirconocenes 2 via multipositional regioisomerization.
Radical formation in the oxidation of 2,2′-azo-2-methyl-6-heptene by thianthrene cation radical
Chen, Tonghua,Shine, Henry J.
, p. 4716 - 4719 (2007/10/03)
Reaction of 2,2′-azo-2-methyl-6-heptene (1) with thianthrene cation radical perchlorate (Th?+ClO4-) in CH2Cl2 solution containing 2,6-di-tert-butyl-4-methylpyridine (DTBMP) gave a mixture of nine C8 hydrocarbons, namely, 1,1,2-trimethylcyclopentane (4, 2.2%), 6-methyl-1-heptene (5, 2.2%), 2-methyl-1,6-heptadiene (6, 9.8%), 2,2-dimethyl-1-methylenecyclopentane (7, 2.9%), 6-methyl-1,5-heptadiene (8, 39%), 3,3-dimethyl- (9, 7.6%), 4,4-dimethyl- (10, 11%), 1,2-dimethyl- (11, 5.4%), and 1,6-dimethylcyclohexene (12, 1.5%). The amounts of acyclic dienes (6, 8) fell and of cyclohexenes (9, 10) rose when DTBMP was omitted from or diminished in the solution. The results provide firm evidence (products 4, 5, and 7) for the formation of the 2-methyl-6-hepten-2-yl radical (2), although the major fate of 2 is its oxidation to the corresponding cation 13, the origin of the bulk of the other products.
Stoichiometric Reactions of Nonconjugated Dienes with Zirconocene Derivatives. Further Delineation of the Scope of Bicyclization and Observation of Novel Multipositional Alkene Regioisomerization
Negishi, Ei-ichi,Maye, John P.,Chouery, Daniele
, p. 4447 - 4462 (2007/10/02)
The reaction of n-Bu2ZrCp2 with nonconjugated dienes containing substituted vinyl groups can lead to either bicyclization or the formation of conjugated diene-zirconocenes via multipositional regioisomerization.
The Thermolysis of 2,2-Dimethyl-1-vinylcyclobutane
Chickos, James S.,Frey, H. Monty
, p. 365 - 370 (2007/10/02)
The kinetics of thermolysis of 2,2-dimethyl-1-vinylcyclobutane have been investigated as a function of temperature from 263 to 301 deg C.Primary products produced in the reaction include isobutene and butadiene, 4,4-dimethylcyclohexene, 2-methylhepta-1,6-diene, and cis-2-methylhepta-1,5-diene. trans-2-Methylhepta-1,5-diene and 2,4-dimethylhexa-1,5-diene are produced from cis-2-methylhepta-1,5-diene by way of a 3,3-sigmatropic rearrangement.The reaction obeys first-order kinetics and is unaffected by surface.Activation energies (kcal mol-1) and (logA/s-1) for the overall decomposition and for formation of the primary products are 45.73 +/- 0.3 (14.427 +/- 0.12), 47.71 +/- 0.7 (15.087 +/- 0.3), 44.35 +/- 1.6 (12.53 +/- 0.6), 45.0 +/-1.3 (12.24 +/- 0.5), and 38.38 +/- 1.7 (10.785 +/- 0.7), respectively.The regiochemistry observed in fragmentation and in the 1,3-sigmatropic rearrangement of the starting material is discussed in terms of substituent effects found in other cyclobutane and vinylcyclobutane thermolyses.The fragmentation process and the isomerization to 4,4-dimethylcyclohexene and 2-methylhepta-1,6-diene is believed to proceed through the intervention of 6-methylhept-1-ene-3,6-diyl. cis-2-Methylhepta-1,5-diene is formed from a concerted 1,5-sigmatropic rearrangement of the starting material.The factors which affect the stereochemistry of the 1,5-hydrogen shift are discussed.
Secondary Deuterium Isotope Effects in the Thermolysis of 2,2-Dimethyl-1-vinylcyclobutane
Chickos, James S.
, p. 1109 - 1112 (2007/10/02)
Secondary deuterium isotope effects for the thermolysis of 2,2-dimethyl-1-vinyl-3,3,4,4-tetradeuteriocyclobutane are reported.A value of kH/kD (262.2 deg C) for the overall decomposition of the starting material of 1.018 +/- 0.008 was determined and values of 1.06 +/- 0.04, 0.95 +/- 0.04, 0.95 +/- 0.08 and 0.98 +/- 0.1 are reported for fragmentation to butadiene and 2-methylpropene, and for rearrangement to 4,4-dimethylcyclohexene, cis-2-methylhepta-1,5-diene, and 2-methylhepta-1,6-diene, respectively.The isotope effects are discussed in terms of the potential energy surfaces proposed for 1,4-biradicals.It is concluded from these results and the isotope effect observed in thermolysis of cyclobutane that most of the effect in cyclobutane results from cleavage of the first bond, and that the subsequent surface for fragmentation is relatively flat.
SELECTIVE REDUCTION OF TERTIARY ALKYL, BENZYL, AND ALLYL HALIDES TO HYDROCARBONS USING LITHIUM 9,9-DI-N-BUTYL-9-BORABICYCLONONANATE
Toi, Hiroo,Yamamoto, Yoshinori,Sonoda, Akio,Murahashi, Shun-Ichi
, p. 2261 - 2268 (2007/10/02)
The title 9-borabicyclononane(9-BBN) ate complex (1) brings about selective removal of tertiary alkyl, benzyl, and allyl halides to give the corresponding hydrocarbons in excellent yields without concomitant attack on secondary, primary and aryl derivatives.The reduction of cis- and trans-4-t-butyl-1-methylcyclohexyl chlorides (2) with 1 gives 4-t-butyl-1-methylcyclohexanes (3) with partial inversion of configuration in cyclohexane, while that in benzene gives thermodynamically trans-3 predominantly.The reactions of 1,1-dimethyl-5-hexenyl chloride (4) and 1,7,7-trimethylbicyclohept-2-yl chloride (8) with 1 proceed with the rearrangements characteristic to a carbonium ion intermediate.The reduction of 1-ethyl-1-methylpentyl chloride with 1 follows a second-order rate equation.
