13363-25-2Relevant academic research and scientific papers
Direct Synthesis of Mono-α-arylated Ketones from Alcohols and Olefins via Ni-Catalyzed Oxidative Cross-Coupling
Yang, Peng-Fei,Shu, Wei
supporting information, p. 6203 - 6208 (2020/08/12)
Controlled synthesis of α-monoarylated ketones is significant yet challenging due to the site-selectivity issues and nonproductive overarylation reactions. Herein, we reported the direct synthesis of α-arylated ketones enabled by Ni-catalyzed dehydrogenative cross-coupling reaction cascade between alcohols and olefins. The use of readily available and cost-effective alcohols and olefins provides a straightforward access to monoarylated ketones in good yields with exclusive selectivity without using any advanced synthetic intermediates.
Homobenzylic Oxygenation Enabled by Dual Organic Photoredox and Cobalt Catalysis
McManus, Joshua B.,Griffin, Jeremy D.,White, Alexander R.,Nicewicz, David A.
supporting information, p. 10325 - 10330 (2020/07/27)
Activation of aliphatic C(sp3)-H bonds in the presence of more activated benzylic C(sp3)-H bonds is often a nontrivial, if not impossible task. Herein we show that leveraging the reactivity of benzylic C(sp3)-H bonds to achieve reactivity at the homobenzylic position can be accomplished using dual organic photoredox/cobalt catalysis. Through a two-part catalytic system, alkyl arenes undergo dehydrogenation followed by an anti-Markovnikov Wacker-type oxidation to grant benzyl ketone products. This formal homobenzylic oxidation is accomplished with high atom economy without the use of directing groups, achieving valuable reactivity that traditionally would require multiple chemical transformations.
Iron-Catalyzed Methylation Using the Borrowing Hydrogen Approach
Polidano, Kurt,Allen, Benjamin D. W.,Williams, Jonathan M. J.,Morrill, Louis C.
, p. 6440 - 6445 (2018/07/25)
A general iron-catalyzed methylation has been developed using methanol as a C1 building block. This borrowing hydrogen approach employs a Kn?lker-type (cyclopentadienone)iron carbonyl complex as catalyst (2 mol %) and exhibits a broad reaction scope. A variety of ketones, indoles, oxindoles, amines, and sulfonamides undergo mono- or dimethylation in excellent isolated yields (>60 examples, 79% average yield).
Nickel-Catalyzed Hydroacylation of Styrenes with Simple Aldehydes: Reaction Development and Mechanistic Insights
Xiao, Li-Jun,Fu, Xiao-Ning,Zhou, Min-Jie,Xie, Jian-Hua,Wang, Li-Xin,Xu, Xiu-Fang,Zhou, Qi-Lin
supporting information, p. 2957 - 2960 (2016/03/19)
The first nickel-catalyzed intermolecular hydroacylation reaction of alkenes with simple aldehydes has been developed. This reaction offers a new approach to the selective preparation of branched ketones in high yields (up to 99%) and branched selectivities (up to 99:1). Experimental data provide evidence for reversible formation of acyl-nickel-alkyl intermediate, and DFT calculations show that the aldehyde C-H bond transfer to a coordinated alkene without oxidative addition is involved. The origin of the reactivity and regioselectivity of this reaction was also investigated computationally, which are consistent with experimental observations.
C-C coupling of ketones with methanol catalyzed by a N-heterocyclic carbene-phosphine iridium complex
Quan, Xu,Kerdphon, Sutthichat,Andersson, Pher G.
supporting information, p. 3576 - 3579 (2015/03/04)
An N-heterocyclic carbene-phosphine iridium complex system was found to be a very efficient catalyst for the methylation of ketone via a hydrogen transfer reaction. Mild conditions together with low catalyst loading (1 mol%) were used for a tandem process which involves the dehydrogenation of methanol, C=C bond formation with a ketone, and hydrogenation of the new generated double bond by iridium hydride to give the alkylated product. Using this iridium catalyst system, a number of branched ketones were synthesized with good to excellent conversions and yields.
One-pot method for α-phenylation of ketones using isoxazolidine and triphenylaluminum
Miyoshi, Tetsuya,Sato, Shohei,Tanaka, Hiroya,Hasegawa, Chihiro,Ueda, Masafumi,Miyata, Okiko
experimental part, p. 4188 - 4191 (2012/08/28)
The efficient one-pot umpolung α-phenylation of ketones via N-alkenylisoxazolidine is described. When the various ketones are treated with triphenylaluminum prepared from phenylmagnesium chloride and AlCl3 in the presence of isoxazolidine, the desired products are obtained in good to moderate yield. This method is equivalent to a direct α-arylation reaction of carbonyl groups.
Templation of the excited-state chemistry of α-(n-alkyl) dibenzyl ketones: how guest packing within a nanoscale supramolecular capsule influences photochemistry
Gibb, Corinne L. D.,Sundaresan, Arun Kumar,Ramamurthy,Gibb, Bruce C.
, p. 4069 - 4080 (2008/12/20)
Excited-state behavior of eight α-alkyl dibenzyl ketones (alkyl = CH3 through n-C8H17) that are capable of undergoing type II and/or type I photoreactions has been explored in isotropic solution and within a water-soluble capsule. The study consisted of two parts: photochemistry that explored the excited-state chemistry and an NMR analysis that revealed the packing of each guest within the capsule. The NMR data (COSY, NOESY, and TOCSY experiments) revealed that ternary complexes between α-alkyl dibenzyl ketones and the capsule formed by two cavitands are kinetically stable, and the guests fall into three packing motifs modulated by the length of the α-alkyl chain. In essence, the host is acting as an external template to promote the formation of distinct guest conformers. The major products from all eight guests upon irradiation either in hexane or in buffer solution resulted from the well-known Norrish type I reaction. However, within the capsule the excited-state chemistry of the eight ketones was dependent on the alkyl chain length. The first group consisted of α-hexyl, α-heptyl, and α-octyl dibenzyl ketones that yielded large amounts of Norrish type II products within the host, while in solution the major products were from Norrish type I reaction. The second group consists of α-butyl and α-pentyl dibenzyl ketones that yield equimolar amounts of two rearranged starting ketones within the capsule (combined yield of ca 60%), while in solution no such products were formed. The third group consisted of α-methyl, α-ethyl, and α-propyl dibenzyl ketones that within the capsule yielded only one (not two) rearranged starting ketone in larger amounts (21-35%) while in solution no rearrangement product was obtained. Variation in the photochemistry of the guest within the capsule, with respect to the α-alkyl chain length of the guest, highlights the importance of how a small variation in supramolecular structure can influence the selectivity within a confined nanoscale reactor.
Stoichiometric hydrogenation of α,β-unsaturated ketones by HCo(CO)4
Roth, Jerome A.,Grega, Kevin,Orchin, Milton
, p. 129 - 136 (2007/10/02)
A study of the kinetics of the stoichiometric hydrogenation of α,β-unsaturated ketones by HCo(CO)4 led to the rate expression rate = kobs2-1.The reaction is catalyzed by Co2(CO)8 and shows a small inverse isotope effect with DCo(CO)4.Although the analogous reaction with the α,β-unsatureted ester dimethyl α-methylidenesuccinate (dimethyl itaconate, DMI) is also catalyzed by Co2(CO)8 and also shows an inverse isotope effect, the rate expression involves a first order dependence on HCo(CO)4.Furthermore, contrary to the behavior of simple acrylates, which have been shown elsewhere to conform to the same kinetic expression, no aldehydic product is produced.A mechanism consistent with the results is proposed.
