60212-39-7Relevant academic research and scientific papers
Olefination via Cu-Mediated Dehydroacylation of Unstrained Ketones
Dong, Guangbin,Xu, Yan,Zhou, Xukai
supporting information, p. 20042 - 20048 (2021/12/03)
The dehydroacylation of ketones to olefins is realized under mild conditions, which exhibits a unique reaction pathway involving aromatization-driven C-C cleavage to remove the acyl moiety, followed by Cu-mediated oxidative elimination to form an alkene between the α and β carbons. The newly adopted N′-methylpicolinohydrazonamide (MPHA) reagent is key to enable efficient cleavage of ketone C-C bonds at room temperature. Diverse alkyl- and aryl-substituted olefins, dienes, and special alkenes are generated with broad functional group tolerance. Strategic applications of this method are also demonstrated.
Cobalt-Catalyzed Decarboxylative Methylation and Ethylation of Aliphatic N-(Acyloxy)phthalimides with Organoaluminum Reagents
Wang, Ze-Zhong,Wang, Guang-Zu,Zhao, Bin,Shang, Rui,Fu, Yao
, p. 1221 - 1225 (2020/08/17)
A cobalt-catalyzed decarboxylative methylation of aliphatic redox-active esters [ N-(acyloxy)phthalimides; RAEs] with trimethylaluminum under mild conditions was developed, providing a method for transforming a carboxylate group into a methyl group without redox fluctuation. Primary and secondary RAEs were both amenable substrates, whereas a tertiary RAE delivered an elimination product. Triethylaluminum was also used to deliver a decarboxylative ethylation product.
Nickel/Cobalt-Catalyzed C(sp3)-C(sp3) Cross-Coupling of Alkyl Halides with Alkyl Tosylates
Komeyama, Kimihiro,Michiyuki, Takuya,Osaka, Itaru
, p. 9285 - 9291 (2019/10/11)
The C(sp3)-C(sp3) cross-coupling of alkyl halides with alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts in the presence of a manganese reductant. This method provides a straightforward route to a diverse set of not only secondary-primary but also primary-primary C(sp3)-C(sp3) linkages under mild conditions without using alkyl-metallic reagents. Mechanistic studies suggest the formation of alkyl radicals from both alkyl halides and alkyl tosylates. Additionally, cross-coupling could be applied to the short-step synthesis of a histone deacetylase inhibitor, Vorinostat.
Quaternary Centers by Nickel-Catalyzed Cross-Coupling of Tertiary Carboxylic Acids and (Hetero)Aryl Zinc Reagents
Chen, Tie-Gen,Zhang, Haolin,Mykhailiuk, Pavel K.,Merchant, Rohan R.,Smith, Courtney A.,Qin, Tian,Baran, Phil S.
, p. 2454 - 2458 (2019/02/09)
This work bridges a gap in the cross-coupling of aliphatic redox-active esters with aryl zinc reagents. Previously limited to primary, secondary, and specialized tertiary centers, a new protocol has been devised to enable the coupling of general tertiary systems using nickel catalysis. The scope of this operationally simple method is broad, and it can be used to simplify the synthesis of medicinally relevant motifs bearing quaternary centers.
Redox-Active Esters in Fe-Catalyzed C-C Coupling
Toriyama, Fumihiko,Cornella, Josep,Wimmer, Laurin,Chen, Tie-Gen,Dixon, Darryl D.,Creech, Gardner,Baran, Phil S.
, p. 11132 - 11135 (2016/10/12)
Cross-couplings of alkyl halides and organometallic species based on single electron transfer using Ni and Fe catalyst systems have been studied extensively, and separately, for decades. Here we demonstrate the first couplings of redox-active esters (both isolated and derived in situ from carboxylic acids) with organozinc and organomagnesium species using an Fe-based catalyst system originally developed for alkyl halides. This work is placed in context by showing a direct comparison with a Ni catalyst for >40 examples spanning a range of primary, secondary, and tertiary substrates. This new C-C coupling is scalable and sustainable, and it exhibits a number of clear advantages in several cases over its Ni-based counterpart.
Organic chemistry: A general alkyl-alkyl cross-coupling enabled by redox-active esters and alkylzinc reagents
Qin, Tian,Cornella, Josep,Li, Chao,Malins, Lara R.,Edwards, Jacob T.,Kawamura, Shuhei,Maxwell, Brad D.,Eastgate, Martin D.,Baran, Phil S.
, p. 801 - 805 (2016/06/01)
Alkyl carboxylic acids are ubiquitous in all facets of chemical science, from natural products to polymers, and represent an ideal starting material with which to forge new connections. This study demonstrates how the same activating principles used for decades to make simple C-N (amide) bonds from carboxylic acids with loss of water can be used to make C-C bonds through coupling with dialkylzinc reagents and loss of carbon dioxide. This disconnection strategy benefits from the use of a simple, inexpensive nickel catalyst and exhibits a remarkably broad scope across a range of substrates (>70 examples).
Synthetic strategy for cyclic amines: A stereodefined cyclic N,O-acetal as a stereocontrol and diversity-generating element
Kim, Haejin,Lim, Wontaeck,Im, Donghong,Kim, Dong-Gil,Rhee, Young Ho
, p. 12055 - 12058 (2013/01/16)
In control: A new synthetic strategy towards cyclic amines was developed and exploits a stereodefined cyclic N,O-acetal as the key stereocontrol and diversity-generating element. The cyclic N,O-acetal was prepared from the sequential asymmetric hydroamina
New Synthetic Approach to Cyclopenta-Fused Heterocycles Based upon a Mild Nazarov Reaction
Occhiato, Ernesto G.,Prandi, Cristina,Ferrali, Alessandro,Guarna, Antonio,Venturello, Paolo
, p. 9728 - 9741 (2007/10/03)
The Pd-catalyzed coupling reaction of lactam or lactone-derived vinyl triflates and phosphates with α-alkoxydienylboronates gives conjugated alkoxytrienes in which one of the double bonds is embedded in a heterocyclic moiety. If subjected to mild acidic hydrolysis, these compounds undergo a 4π electrocyclization process (Nazarov reaction) which furnishes cyclopenta-fused O- and N-heterocycles in good yields. The scope of the work has been that of closely examining the role and effect of both the heteroatom and the heterocycle ring size on the outcome of the electrocyclization, as well as the torquoselectivity of this process. The presence of the heteroatom was essential in stabilizing the oxyallyl cation intermediate, thus allowing the reaction to occur. The ring size was also a basic parameter in the cyclization step: five-membered azacycles required more drastic conditions to give 5-5 fused systems and did so only after an initial hydrolysis to the corresponding divinyl ketones. As for the torquoselectivity, with both 2-methyl and 4-methyl substituted lactam derivatives steric interactions seem to have a role in forcing the conrotatory process to take place in one sense only: allowing the synthesis of diastereomerically pure compounds to be realized. Because different patterns of substitution on the heterocycle are compatible with the reaction conditions, the methodology developed could be very useful for the synthesis of natural products and biologically active compounds containing cyclopenta-fused O- and N-heterocycle moieties.
