36702-38-2Relevant academic research and scientific papers
Electrochemically driven desaturation of carbonyl compounds
Gnaim, Samer,Takahira, Yusuke,Wilke, Henrik R.,Yao, Zhen,Li, Jinjun,Delbrayelle, Dominique,Echeverria, Pierre-Georges,Vantourout, Julien C.,Baran, Phil S.
, p. 367 - 372 (2021/03/31)
Electrochemical techniques have long been heralded for their innate sustainability as efficient methods to achieve redox reactions. Carbonyl desaturation, as a fundamental organic oxidation, is an oft-employed transformation to unlock adjacent reactivity through the formal removal of two hydrogen atoms. To date, the most reliable methods to achieve this seemingly trivial reaction rely on transition metals (Pd or Cu) or stoichiometric reagents based on I, Br, Se or S. Here we report an operationally simple pathway to access such structures from enol silanes and phosphates using electrons as the primary reagent. This electrochemically driven desaturation exhibits a broad scope across an array of carbonyl derivatives, is easily scalable (1–100 g) and can be predictably implemented into synthetic pathways using experimentally or computationally derived NMR shifts. Systematic comparisons to state-of-the-art techniques reveal that this method can uniquely desaturate a wide array of carbonyl groups. Mechanistic interrogation suggests a radical-based reaction pathway. [Figure not available: see fulltext.]
Bronsted Acid Mediated Direct α-Hydroxylation of Cyclic α-Branched Ketones
Shevchenko, Grigory A.,Dehn, Stefanie,List, Benjamin
supporting information, p. 2298 - 2300 (2018/10/20)
We report a Bronsted acid mediated direct α-hydroxylation of cyclic α-branched ketones via a tandem aminoxylation/N-O bond-cleavage process. Nitrosobenzene is used as the oxidant and subsequently promotes the liberation of the free alcohol. The desired pr
Platinum-Catalyzed Desaturation of Lactams, Ketones, and Lactones
Chen, Ming,Rago, Alexander J.,Dong, Guangbin
supporting information, p. 16205 - 16209 (2018/11/23)
The development of a general platinum-catalyzed desaturation of N-protected lactams, ketones, and lactones to their conjugated α,β-unsaturated counterparts is reported. The reaction operates under mildly acidic conditions at room temperature or 50 °C. It is scalable and tolerates a wide range of functional groups. The complementary reactivity to the palladium-catalyzed desaturation is demonstrated in the efficient conversion of iodide, bromide, and sulfur-containing substrates.
A boron-based synthesis of the natural product (+)-trans- dihydrolycoricidine
Poe, Sarah L.,Morken, James P.
supporting information; experimental part, p. 4189 - 4192 (2011/06/20)
Diastereoselective diboration results in the highly selective 1,4-dihydroxylation of chiral cyclohexadienes (see scheme). Together with the catalytic enantioselective conjugate allylboration, the diene diboration facilitates the asymmetric synthesis of the cytotoxic agent (+)-trans- dihydrolycoricidine (1). pin=pinacol. Copyright
Synthesis of cyclic enones via direct palladium-catalyzed aerobic dehydrogenation of ketones
Diao, Tianning,Stahl, Shannon S.
supporting information; experimental part, p. 14566 - 14569 (2011/10/17)
α,β-Unsaturated carbonyl compounds are versatile intermediates in the synthesis of pharmaceuticals and biologically active compounds. Here, we report the discovery and application of Pd(DMSO)2(TFA)2 as a catalyst for direct dehydrogenation of cyclohexanones and other cyclic ketones to the corresponding enones, using O2 as the oxidant. The substrate scope includes heterocyclic ketones and several natural-product precursors.
Palladium-catalyzed regioselective arylation of silyloxy compounds with triarylantimony diacetates
Kang, Suk-Ku,Ryu, Hyung-Chul,Honge, Young-Taek
, p. 3350 - 3351 (2007/10/03)
The regioselective arylation of silyloxy compounds with triarylantimony diacetates was performed by using palladium catalysts. The silyl enol ether, silyl dienol ethers and silyl oxycyclopropane were arylated in the presence of a palladium catalysts with triarylantimony(V) diacetates under mild conditions. The results showed that the given method had the advantage of mild conditions which involved the use of PdCl2 at room temperature even in the presence of water.
Applications of the β-azidonation reaction to organic synthesis. α,β- Enones, conjugate addition, and γ-lactam annulation
Magnus, Philip
, p. 12486 - 12499 (2007/10/03)
The β-azido functionalization reaction provides a mechanistically different enone synthesis that involves treatment of 2 with fluoride anion to effect desilylation and concomitant β-elimination to give 3. Table 1 lists a number of examples of the direct conversion of a TIPS enol ether into the corresponding α,β-enone via a β-azido TIPS enol ether. The β-azido group can be ionized with Me3Al or Me2AlCl and the intermediate enonium ion trapped by a variety of nucleophiles such as an allylstannane, electron-rich aromatics, TMS enol ethers, Et2AlCN, Me2AlCCR, Me4AlLi, and vinylaluminum reagents to give the products listed in Table 2. The diastereoselectivity of the reaction of a 4-substituted enonium ion with indole shows an unusual increase of selectivity with increasing temperature. Reduction of the azide 2 provides access to β-amino TIPS enol ethers 5, which, for example, can be converted into a cinnamide derivative and cyclized via a putative 'ene' process into a γ-lactam.
Intramolecular Cooperative Reactions of 1,2-Bis(diazoketone)s. The First Syntheses of trans-Hydro-1H-2-inden-1-ones
Nakatani, Kazuhiko,Takada, Kazunori,Isoe, Sachihiko
, p. 2466 - 2473 (2007/10/02)
The intramolecular cooperative reactions of 1,2-bis(diazoketone)s initiated by the Wolff rearrangement of α-diazoketones have been investigated.Under thermal conditions, 1,2-bis(diazoketone)s are efficiently transformed into 2-cyclopenten-1-one derivatives with complete stereospecificity.Thus, a most extraordinary result is reported, that trans-hydro-2-inden-1-ones (1-3) were synthesized for the first time from trans-1,2-bis(diazoketone)s (5, 11, and 12), respectively.The unprecedented trans-hydroindenone structure was confirmed by X-ray analysis of 3 as well as 1H NMR analysis and was supported by ab initio molecular orbital calculations.The same reactions were also carried out under photochemical conditions and were applied to 1,3-bis(diazoketone)s, giving 2-cyclohexen-1-one derivatives.
Novel Synthesis of trans-Hydroindenones by Thermal Reaction of α,ω-Bis(diazo)diketones
Nakatani, Kazuhiko,Takada, Kazunori,Odagaki, Yoshihiko,Isoe, Sachihiko
, p. 556 - 557 (2007/10/02)
Thermal reaction of α,ω-bis(diazo)diketones gives α,β-unsaturated cycloalkenones including unsubstituted trans-hydroindenones, which were difficult to access by the conventional synthetic reactions.
