13757-43-2Relevant articles and documents
Corey,Shulaman
, p. 3655 (1968)
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Bach,R.D. et al.
, p. 1955 - 1963 (1972)
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6. 1. 0.
Wiberg,Lupton Jr.,Wasserman,de Meijere,Kass
, p. 1740 - 1744 (1984)
The enthalpies of formation of cis- and trans-1,2-diethylcyclopropane were determined by oxygen bomb calorimetry. The cis-diethyl isomer was 1. 1 kcal/mol less stable than the trans isomer. Alkyl groups were found to stabilize a cyclopropane ring by the same amount as for a carbon-carbon double bond. The enthalpies of formation cis- and trans-bicyclo left bracket 6. 10 right bracket nonane also were determined by oxygen bomb calorimetry. The two bicyclo left bracket 6. 1. 0 right bracket nonanes have essentially the same enthalpies of formation, in contrast to cis- and trans-cyclooctene. The introduction of a trigonal center makes the trans-bicyclononane 3 kcal/mol less stable than the cis isomer. Molecular mechanics calculations are reported for a series of cis- and trans-bicyclo left bracket n. 1. 0 right bracket alkanes. In order to better estimate the strain energy of trans-bicyclo left bracket 4. 1. 0 left bracket heptane, the difference in energy between it and its cis isomer was calculated via ab initio molecular orbital theory.
Mild Ring-Opening 1,3-Hydroborations of Non-Activated Cyclopropanes
Wang, Di,Xue, Xiao-Song,Houk, Kendall N.,Shi, Zhuangzhi
supporting information, p. 16861 - 16865 (2018/11/27)
The Brown hydroboration reaction, first reported in 1957, is the addition of B?H across an olefin in an anti-Markovnikov fashion. Here, we solved a long-standing problem on mild 1,3-hydroborations of non-activated cyclopropanes. A three-component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring-opening of cyclopropanes following the anti-Markovnikov rule, under mild reaction conditions. Density functional theory (M06-2X) calculations show that the preferred pathway involves a cationic boron intermediate which is quenched by hydride transfer from the silane.
A palladium-catalyzed methylenation of olefins using halomethylboronate reagents
Hartog, Tim Den,Toro, Juan Manuel Sarria,Chen, Peter
supporting information, p. 1100 - 1103 (2014/03/21)
Methylenation of electron-rich olefins is a highly challenging reaction, for which we have developed a new methodology exploiting Pd-catalysis and halomethylboronate reagents, the latter replacing diazomethane and zinc carbenoids as methylene donors. Optimization of the reaction for norbornene and extension to several other olefins are reported, with reasonable-to-excellent yields of cyclopropanes in combination with β-H elimination products. Several mechanisms are plausible for this methylenation reaction.
