- Rhoda-Electrocatalyzed Bimetallic C?H Oxygenation by Weak O-Coordination
-
Rhodium-electrocatalyzed arene C?H oxygenation by weakly O-coordinating amides and ketones have been established by bimetallic electrocatalysis. Likewise, diverse dihydrooxazinones were selectively accessed by the judicious choice of current, enabling twofold C?H functionalization. Detailed mechanistic studies by experiment, mass spectroscopy and cyclovoltammetric analysis provided support for an unprecedented electrooxidation-induced C?H activation by a bimetallic rhodium catalysis manifold.
- Tan, Xuefeng,Massignan, Leonardo,Hou, Xiaoyan,Frey, Johanna,Oliveira, Jo?o C. A.,Hussain, Masoom Nasiha,Ackermann, Lutz
-
supporting information
p. 13264 - 13270
(2021/05/06)
-
- Iron-Catalyzed, Iminyl Radical-Triggered Cascade 1,5-Hydrogen Atom Transfer/(5+2) or (5+1) Annulation: Oxime as a Five-Atom Assembling Unit
-
By integration of iminyl radical-triggered 1,5-hydrogen atom transfer and (5+2) or (5+1) annulation processes, a series of structurally novel and interesting azepine and spiro-tetrahydropyridine derivatives have been successfully prepared in moderate to good yields. This method utilizes FeCl2 as the catalyst and readily available oximes as five-atom units, while showcasing broad substrate scope and good functional group compatibility. The annulation products can be easily converted into many valuable compounds. Moreover, DFT calculation studies are performed to provide some insights into the possible reaction mechanisms for the (5+2) and (5+1) annulations.
- Chen, Ying-Chun,Du, Fei,Jiang, Kun,Liang, Wu,Ouyang, Qin,Shuai, Li,Wei, Ye,Yang, Jie
-
supporting information
p. 19222 - 19228
(2020/08/25)
-
- Iridium-Catalyzed C-H Amination of Weinreb Amides: A Facile Pathway toward Anilines and Quinazolin-2,4-diones
-
C-H amination of arenes directed by weakly coordinating Weinreb amides has been achieved with an iridium catalyst and 2,2,2-trichloroethoxycarbonyl (Troc) azide as an aminating agent, providing a robust method of producing synthetic useful ortho-TrocNH aryl Weinreb amides. Taking advantage of the reactivity of Weinreb amide and Troc groups in the amination products, selective hydrolysis was achieved as an attractive process for the synthesis of ortho-NH2 aryl Weinreb amides, which are the building blocks useful in the synthesis of bioactive compounds, and cascade aminocyclization with primary amines was successful and provided an efficient pathway for the construction of quinazolin-2,4-diones, which are present in various alkaloids and natural products.
- Dong, Xunqing,Ma, Panpan,Zhang, Tao,Jalani, Hitesh B.,Li, Guigen,Lu, Hongjian
-
p. 13096 - 13107
(2020/11/26)
-
- Fluoro-Substituted Methyllithium Chemistry: External Quenching Method Using Flow Microreactors
-
The external quenching method based on flow microreactors allows the generation and use of short-lived fluoro-substituted methyllithium reagents, such as fluoromethyllithium, fluoroiodomethyllithium, and fluoroiodostannylmethyllithium. Highly chemoselective reactions have been developed, opening new opportunities in the synthesis of fluorinated molecules using fluorinated organometallics.
- Colella, Marco,Degennaro, Leonardo,Higuma, Ryosuke,Ishikawa, Susumu,Luisi, Renzo,Nagaki, Aiichiro,Takahashi, Yusuke,Tota, Arianna
-
supporting information
p. 10924 - 10928
(2020/05/08)
-
- Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
-
An efficient, broadly applicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields. This method notably enables an easy cleavage of oxazolidinone-based auxiliaries.
- Guissart, Céline,Barros, Andre,Rosa Barata, Luis,Evano, Gwilherm
-
supporting information
p. 5098 - 5102
(2018/09/13)
-
- Selective deprotection and amidation of 2-pyridyl esters via N-methylation
-
The 2-pyridyl residue serves as a protecting group for various carboxylic acids. The protecting group is selectively cleaved under mild conditions via N-methylation of the pyridyl group. During the deprotection process, the various functional groups as we
- Yamada, Shinji,Abe, Misato
-
experimental part
p. 8667 - 8671
(2011/01/04)
-
- The first general and selective palladium(II)-catalyzed alkoxycarbonylation of arylboronates: Interplay among benzoquinone-ligated palladium(0) complex, organoboron, and alcohol solvent
-
Methoxycarbonylation of aryl- and alken-ylboron compounds was performed using the palladium (II) acetate/triphenylphosphine [PdACHTUNGTRENNUNG(OAc) 2/PPh3] catalyst with p-benzoquinone as a stoichiometric oxidant in methanol at ambient temperature to obtain the corresponding methyl esters in good yields. A wide variety of functional groups including various carbonyl functionalities, nitrile, nitro, sulfone, and unprotected pyrrole rings were tolerated in the methoxycarbonlation, while the use of higher alcohols except for tert-butanol afforded various pchlorobenzoates in moderate to high yields. The catalytic alkoxycarbonylation proceeded without any acid or base additive, and an oxidative transmetalation step is proposed to explain the exceptional efficacy of this protocol. DFT and MP2 calculations support the proposed mechanism.
- Yamamoto, Yoshihiko
-
supporting information; experimental part
p. 478 - 492
(2010/07/03)
-
- GLUCAGON RECEPTOR ANTAGONISTS, PREPARATION AND THERAPEUTIC USES
-
The present invention discloses novel compounds of Formula I, or pharmaceutically acceptable salts thereof, which have glucagon receptor antagonist or inverse agonist activity, as well as methods for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising compounds of Formula I as well as methods of using them to treat diabetic and other glucagon related metabolic disorders, and the like.
- -
-
Page/Page column 41
(2010/02/15)
-
- Synthesis of novel retinoid X receptor-selective retinoids
-
Retinoids 1-5 have been identified as potent RXR agonists for evaluation in the treatment of non-insulin-dependent (type II) diabetes mellitus (NIDDM). Highly convergent syntheses of 1-5 have been developed. The core tetrahydronaphthalene 7, employed in the synthesis of 1 and 2, was prepared in 98% yield using an AlCl3-catalyzed (0.03 equiv) Friedel-Crafts alkylation of toluene with 2,5-dichloro-2,5-dimethylhexane 6. A nitromethane-mediated Fridel-Crafts acylation of 7 with chloromethylnicotinate 9 was developed to prepare ketone 10 in 68% yield. Chelate-controlled addition of MeMgCl to 10 followed by dehydration afforded olefin 11 in 65% yield. Cyclopropanation of 11 with trimethylsulfoxonium ylide, followed by saponification, completed a five-step synthesis of 1 in 33% yield. FeCl3-catalyzed (0.05 equiv) Friedel-Crafts acylation of 7 with chloromethyl-terephthalate 14 afforded ketone 15 in 81% yield. Saponification of 15 and reaction with 50% aqueous NH2OH in AcOH afforded a 9:1 mixture of cis and trans oximes, from which the desired cis-oxime 2 was isolated in 43% yield. The core bromo-dihydronaphthalene 29 required for the synthesis of 3-5 was prepared by a Shapiro reaction. Transmetalation of 29 and reaction with Weinreb amides 30b or 36 afforded ketones 32 and 37, which were converted into 3-5 using chemistry comparable to the tetrahydronaphthylene series. Suzuki coupling of boronic acids 41 and 42 with vinyl triflate 43 provided an alternative approach to the synthesis of this class of compounds.
- Faul,Ratz,Sullivan,Trankle,Winneroski
-
p. 5772 - 5782
(2007/10/03)
-
- Palladium-catalyzed coupling reactions of N-methoxy-N-methylcarbamoyl chloride for the synthesis of N-methoxy-N-methylamides
-
A new synthetic method of N-methoxy-N-methylamides is developed. The palladium-catalyzed coupling reaction of N-methoxy-N-methylcarbamoyl chloride furnished N-methoxy-N-methylamide in moderate to good yield, wherein a carbonyl equivalent was appended to s
- Murakami, Masahiro,Hoshino, Yujiro,Ito, Hajime,Ito, Yoshihiko
-
p. 163 - 164
(2007/10/03)
-