71647-37-5Relevant academic research and scientific papers
Organocatalyzed Birch Reduction Driven by Visible Light
Cole, Justin P.,Chen, Dian-Feng,Kudisch, Max,Pearson, Ryan M.,Lim, Chern-Hooi,Miyake, Garret M.
supporting information, p. 13573 - 13581 (2020/09/03)
The Birch reduction is a powerful synthetic methodology that uses solvated electrons to convert inert arenes to 1,4-cyclohexadienes - valuable intermediates for building molecular complexity. Birch reductions traditionally employ alkali metals dissolved in ammonia to produce a solvated electron for the reduction of unactivated arenes such as benzene (Ered -3.42 V vs SCE). Photoredox catalysts have been gaining popularity in highly reducing applications, but none have been reported to demonstrate reduction potentials powerful enough to reduce benzene. Here, we introduce benzo[ghi]perylene imides as new organic photoredox catalysts for Birch reductions performed at ambient temperature and driven by visible light from commercially available LEDs. Using low catalyst loadings (1 mol percent), benzene and other functionalized arenes were selectively transformed to 1,4-cyclohexadienes in moderate to good yields in a completely metal-free reaction. Mechanistic studies support that this unprecedented visible-light-induced reactivity is enabled by the ability of the organic photoredox catalyst to harness the energy from two visible-light photons to affect a single, high-energy chemical transformation.
Scalable and safe synthetic organic electroreduction inspired by Li-ion battery chemistry
Peters, Byron K.,Rodriguez, Kevin X.,Reisberg, Solomon H.,Beil, Sebastian B.,Kawamata, Yu,Baran, Phil S.,Hickey, David P.,Klunder, Kevin,Gorey, Timothy J.,Anderson, Scott L.,Minteer, Shelley D.,Collins, Michael,Starr, Jeremy,Chen, Longrui,Udyavara, Sagar,Neurock, Matthew
, p. 838 - 845 (2019/04/30)
Reductive electrosynthesis has faced long-standing challenges in applications to complex organic substrates at scale. Here, we show how decades of research in lithium-ion battery materials, electrolytes, and additives can serve as an inspiration for achieving practically scalable reductive electrosynthetic conditions for the Birch reduction. Specifically, we demonstrate that using a sacrificial anode material (magnesium or aluminum), combined with a cheap, nontoxic, and water-soluble proton source (dimethylurea), and an overcharge protectant inspired by battery technology [tris(pyrrolidino)phosphoramide] can allow for multigram-scale synthesis of pharmaceutically relevant building blocks. We show how these conditions have a very high level of functional-group tolerance relative to classical electrochemical and chemical dissolving-metal reductions. Finally, we demonstrate that the same electrochemical conditions can be applied to other dissolving metal-type reductive transformations, including McMurry couplings, reductive ketone deoxygenations, and epoxide openings.
Reductions of benzene derivatives whose benzylic positions bear oxygen atoms under mild conditions
Menzek, Abdullah,Karakaya, Melek Goekmen,Kaya, Afsin Ahmet
experimental part, p. 2299 - 2307 (2009/03/12)
Reductions of compounds whose benzylic positions bear O-atoms, such as benzyl alcohol, dibenzyl ether, styrene oxide, benzaldehyde, acetophenone, and benzophenone, to the corresponding non-conjugated dienes were performed by using t-BuOH, Li, and gaseous
Synthesis and reactivity of trans-tricyclo[4.2.0.0]oct-4-ene
Koltun, Elena S.,Kass, Steven R.
, p. 3530 - 3537 (2007/10/03)
The first synthesis of trans-tricyclo[4.2.0.0]oct-4-ene (1), an ethenyl bridged spirohexane, was accomplished in four steps starting from Carpino et al. gem-dichloro ketone 6. An X-ray crystal structure of 1 with one substituent was obtained to provide geometry data on this novel ring system and to confirm the stereochemical assignment of the penultimate synthetic intermediate. Tricyclo[4.2.0.0]oct-4-ene is surprisingly stable. It reacts with glacial acetic acid but only slowly at 145 °C; the products were isolated and identified. A unimolecular rearrangement takes place at elevated temperatures (165 °C and higher), presumably, via a biradical intermediate to afford tricyclo[4.2.0.0]oct-3-ene (23). The structure of this 1,5-bridged bicyclo[2.1.0]pentane derivative was established by NMR and an X-ray crystal structure of its Diels-Alder adduct with isobenzofuran. Tricyclo[4.2.0.0]oct- 4-ene equilibrates with 23, so equilibrium constants and reaction rates were measured over a 20 °C temperature range from 180 °C to 200 °C. The difference in the heats of formation (ΔΔH°(f) (23 - 1)) is -2.1 kcal/mol, which is in good agreement with ab initio (HF and MP2) calculations using the 6-31G(d) basis set (-1.9 (HF) and -1.4 (MP2) kcal/mol). Computations on trans-tricyclo[4.2.0.0]octane and spirohexane also were carried out, and the structures and energies were compared.
1-VINYLBENZENE 1,2- AND 3,4-OXIDES
Watanabe, Tadashi,Hiratsuka, Akira,Aizawa, Toshiko,Sawahata, Tadashi
, p. 1185 - 1188 (2007/10/02)
Synthesis of highly unstable vinyl-substituted benzene oxides has been established.
