13404-83-6Relevant academic research and scientific papers
Rhodium-Catalyzed Regioselective and Chemoselective Deoxygenative Reduction of 1,3-Diketones
Guo, Xueying,Li, Ruolin,Lin, Zhenyang,Tao, Lei,Zhang, Bing,Zhao, Wanxiang
, p. 4640 - 4647 (2022/05/02)
The deoxygenative reduction of carbonyl compounds has been well established. However, most protocols developed typically require harsh reaction conditions or highly reactive/toxic reagents, and the deoxygenative reduction of 1,3-diketones is rarely explored despite their importance to synthetic chemistry and materials science. We describe here a rhodium-catalyzed regioselective and chemoselective deoxygenative reduction of 1,3-diketones under mild reaction conditions. This approach exhibited exceptionally high regioselectivity toward the aliphatic carbonyl reduction over aromatic carbonyl reduction. Moreover, the reaction showed good functional group tolerance and broad substrate scope as well as great potential in the late-stage modification and synthesis of natural products and pharmaceutical skeletons. Preliminary mechanistic studies and DFT calculations revealed that this reaction involved the deoxygenation of 1,3-diketone to α, β-unsaturated ketone and its subsequent 1,4-reduction. The noticeably lower energy barrier of the aliphatic C═O insertion into [Rh]-Bpin versus the aromatic C═O insertion was responsible for the high regioselectivity in this reduction.
Iridium-Catalyzed Asymmetric Hydrogenation of α-Fluoro Ketones via a Dynamic Kinetic Resolution Strategy
Tan, Xuefeng,Wen, Jialin,Zeng, Weijun,Zhang, Xumu
supporting information, p. 7230 - 7233 (2020/10/02)
The discrimination of a fluorine atom from a hydrogen atom has been challenging in asymmetric catalysis. We herein report iridium-catalyzed hydrogenation of α-fluoro ketones using a strategy of dynamic kinetic resolution. Both enantiomeric and diastereomeric selectivities were satisfactory in the preparation of β-fluoro alcohols. The DFT calculation revealed a C-F···Na charge-dipole interaction in the transition state of hydride transfer. This noncovalent interaction would be responsible for the diastereomeric control.
Palladium-Catalyzed Carbonylative Coupling of Aryl Iodides with Alkyl Bromides: Efficient Synthesis of Alkyl Aryl Ketones
Peng, Jin-Bao,Chen, Bo,Qi, Xinxin,Ying, Jun,Wu, Xiao-Feng
supporting information, p. 4153 - 4160 (2018/09/21)
Alkyl aryl ketones are important structures with applications in many areas of chemistry. Hence, efficient procedures for their production are particularly attractive. In this communication, a general and efficient carbonylative cross-coupling of aryl iodides and unactivated alkyl bromides is presented. By using a simple palladium catalyst, a series of alkyl aryl ketones were synthesized in moderate to excellent yields from readily available alkyl and aryl halides in an In-Ex tube with formic acid as the CO source. In this study both primary and secondary alkyl bromides/iodides were suitable coupling partners. Additionally, this method can also be employed for the late-stage functionalization of complex natural products and polyfunctionalized molecules. (Figure presented.).
PYRIDAZINONE COMPOUNDS AS CALCILYTICS
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Page/Page column 27-28, (2010/11/27)
Various calcilytic compounds and pharmaceutical compositions containing these compounds are disclosed. Calcilytic compounds are compounds capable of inhibiting calcium receptor activity. Methods for preparing calcilytic compounds, oral bioavailability of calcilytic compounds, and their use as calcium receptor antagonists are also disclosed.
Metal bis(perfluorooctanesulfonyl)amides as highly efficient Lewis acid catalysts for fluorous biphase organic reactions
Hao, Xiuhua,Yoshida, Akihiro,Nishikido, Joji
, p. 193 - 199 (2007/10/03)
In fluorous biphase system, metal bis(perfluorooctanesulfonyl)amides are better Lewis acid catalysts than the analogous triflates toward either transesterifications, or direct esterifications, or Friedel-Crafts acylations or Baeyer-Villiger oxidations. These catalysts are selectively soluble in lower fluorous phase and can be recovered simply by phase separation. Furthermore, these catalysts can be reused without decrease of activity in most cases.
Hf[N(SO2C8F17)2] 4-catalyzed Friedel-Crafts acylation in a fluorous biphase system
Hao, Xiuhua,Yoshida, Akihiro,Nishikido, Joji
, p. 2697 - 2700 (2007/10/03)
In a fluorous biphase system, Hf[N(SO2C8F 17)2]4 complex (1 mol %) catalyzes Friedel-Crafts acylation of aromatic compounds such as anisole, toluene and chlorobenzene, and the corresponding aromatic ketones are obtained in satisfactory to high yields. The catalyst is selectively soluble in lower fluorous phase and can be easily recovered by simple phase separation. Furthermore, the catalyst can be reused without decrease of activity in most cases.
Efficient acylation of toluene and anisole with aliphatic carboxylic acids catalysed by heteropoly salt Cs2.5H0.5PW12O40
Kaur, Jaspal,Kozhevnikov, Ivan V.
, p. 2508 - 2509 (2007/10/03)
Heteropoly salt Cs2.5H0.5PW12O40 is a highly efficient and reusable solid acid catalyst for the liquid-phase acylation of toluene or anisole with C2 - C12 aliphatic carboxylic acids.
HENRY CONDENSATION UNDER HIGH PRESSURE. 2. EFFECT OF AROMATIC ALDEHYDE TYPE AND PRESSURE ON THE YIELD OF ω-NITROSTYRENES AND SECONDARY PROCESSES
Agafonov, N. E.,Sedishev, I. P.,Dudin, A. V.,Kutin, A. A.,Stashina, G. A.,Zhulin, V. M.
, p. 366 - 372 (2007/10/02)
Condensation of aromatic aldehydes (I)-(XX) with EtNO2 and n-PrNO2 in AcOH in the presence of AcONH4 or i-BuNH2 gives primarily ω-nitrostyrenes (Ia, b) - (XXa, b) and small quantities of nitriles (Ic) - (XXc), oximes (Id) - (XXd), and ketones (Ie, f) - (XXe, f).The yields of (Ia, b) - (XXa, b) at P = 1 atm are higher for acceptor substitutents on the aromatic ring whereas at P = 10 kbar, they are higher for donor substituents.High pressures suppress the formation of (Ic-f) - (XXc-f) and the Z-isomers of (Ia, b) - (XXa, b).The high pressure technique is especially useful in the preparation of donor-substituted (Ia, b) - (XXa, b) which are intermediates in the synthesis of the psychotropic β-phenylethylamines.
Trifluoroacetic Acid-catalysed Transacylation of Arenes by Acylpentamethylbenzene
Keumi, Takashi,Morita, Toshio,Shimada, Takanobu,Teshima, Naomi,Kitajima, Hidehiko,Prakash, G. K. Surya
, p. 847 - 852 (2007/10/02)
Facile transacylation between acylpentamethylbenzene and activated arenes such as anisole was found to occur in boiling trifluoroacetic acid (TFA).The mechanism for the transacylation between acetylpentamethylbenzene (AcPMB) and anisole with TFA was elucidated by means of product isolation and kinetics.The reaction proceeds via reversible protodeacetylation of AcPMB involving an ipso-protonated intermediate B to give pentamethylbenzene and acetic trifluoroacetic anhydride followed by irreversible acetylation of anisole by the mixed anhydride.The mechanism resulting in an ipso-protonated intermediate B was deduced from the reaction of acetylmesitylene with TFA as well as from the rate of deacetylation of 3,5-dideuterioacetylmesitylene with TFA.The formation of such an intermediate was also independently confirmed by 13C n.m.r. spectroscopic syudies on AcPMB in superacid solutions under stable conditions.
