21550-06-1Relevant academic research and scientific papers
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.
Acylation of aryl halides and α-bromo acetates with aldehydes enabled by nickel/tbadt cocatalysis
Fan, Pei,Zhang, Chang,Zhang, Linchuan,Wang, Chuan
supporting information, p. 3875 - 3878 (2020/05/14)
In this protocol aryl halides and α-bromo acetates are efficiently cross-coupled with an array of (hetero)aromatic and aliphatic aldehydes under the cooperative catalysis of nickel and tetrabutylammonium decatungstate as a hydrogen-atom-transfer photocatalyst. This method provides a concise approach to a variety of ketones with high compatibility of various functional groups.
Conversion of Aldehydes to Branched or Linear Ketones via Regiodivergent Rhodium-Catalyzed Vinyl Bromide Reductive Coupling-Redox Isomerization Mediated by Formate
Swyka, Robert A.,Shuler, William G.,Spinello, Brian J.,Zhang, Wandi,Lan, Chunling,Krische, Michael J.
supporting information, p. 6864 - 6868 (2019/05/10)
A regiodivergent catalytic method for direct conversion of aldehydes to branched or linear alkyl ketones is described. Rhodium complexes modified by PtBu2Me catalyze formate-mediated aldehyde-vinyl bromide reductive coupling-redox isomerization to form branched ketones. Use of the less strongly coordinating ligand, PPh3, promotes vinyl-to allylrhodium isomerization en route to linear ketones. This method bypasses the 3-step sequence often used to convert aldehydes to ketones involving the addition of pre-metalated reagents to Weinreb or morpholine amides.
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.).
Dirhodium(ii)/P(t-Bu)3 catalyzed tandem reaction of α,β-unsaturated aldehydes with arylboronic acids
Ma, Ziling,Wang, Yuanhua
supporting information, p. 7470 - 7476 (2018/10/24)
Phosphine ligated dirhodium(ii) acetate is advocated as a catalyst for the synthesis of aryl alkyl ketones by the tandem reaction of α,β-unsaturated aromatic or aliphatic aldehydes with arylboronic acids. This tandem procedure included arylation followed by the isomerization reaction. This method exhibits good functional group tolerance and has a broad substrate scope. With the conjugated aldehydes, the one-step synthesis of γ,δ-unsaturated ketones was realized through this reaction. It is noteworthy that the length of the Rh-P bond is an important factor affecting catalytic reactions. The comparative analysis of the crystal structures of axially alkylphosphane and arylphosphane ligated dirhodium(ii) acetate revealed that the shorter Rh-P bond length favors the isomerization process as compared to the longer one. In addition, the dirhodium(ii) compound can be recovered after the completion of the reaction.
CHEMICAL COMPOUNDS
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, (2008/06/13)
The present invention discloses novel compounds with a variety of therapeutic uses. More particularly, the invention discloses novel symmetrical triphenyl compounds that are particularly useful for selective estrogen receptor modulation.
CHEMICAL COMPOUNDS
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Page/Page column 36, (2008/06/13)
The present invention discloses to novel compounds with a variety of therapeutic uses. More particularly, the invention discloses novel symmetrical triphenyl compounds that are particularly useful for selective estrogen receptor modulation.
Regioselective, directed meta acylation of aromatic compounds
Akai, Shuji,Peat, Andrew J.,Buchwald, Stephen L.
, p. 9119 - 9125 (2007/10/03)
A new method for the directed meta acylation of aromatic compounds is described. This method involves an ortho lithiation procedure combined with zirconocene-benzyne chemistry. 3-Acyl-1-substituted benzene derivatives were obtained by acidic hydrolysis of the azazirconacycle intermediate which results from the coupling of a nitrile with a zirconocene-benzyne complex. Similarly, 3-acyl-2-iodo-1-substituted benzene derivatives were obtained by the iodination of the same intermediate followed by acidic hydrolysis. These procedures, which utilize simple, readily available starting materials, give good yields of regiochemically pure products.
