813-58-1Relevant academic research and scientific papers
Ligand-Enabled γ-C(sp3)?H Olefination of Free Carboxylic Acids
Ghiringhelli, Francesca,Ghosh, Kiron Kumar,Mondal, Arup,Uttry, Alexander,Wedi, Philipp,van Gemmeren, Manuel
, p. 12848 - 12852 (2020/06/25)
We report the ligand-enabled C?H activation/olefination of free carboxylic acids in the γ-position. Through an intramolecular Michael addition, δ-lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium-catalyzed activation of free carboxylic acids in the γ-position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.
Nickel-catalyzed site-selective alkylation of unactivated C(sp 3)-H bonds
Wu, Xuesong,Zhao, Yan,Ge, Haibo
supporting information, p. 1789 - 1792 (2014/03/21)
The direct alkylation of unactivated sp3 C-H bonds of aliphatic amides was achieved via nickel catalysis with the assist of a bidentate directing group. The reaction favors the C-H bonds of methyl groups over the methylene C-H bonds and tolerates various functional groups. Moreover, this reaction shows a predominant preference for sp3 C-H bonds of methyl groups via a five-membered ring intermediate over the sp2 C-H bonds of arenes in the cyclometalation step.
Copper-catalyzed site-selective intramolecular amidation of unactivated C(sp3)-H bonds
Wu, Xuesong,Zhao, Yan,Zhang, Guangwu,Ge, Haibo
supporting information, p. 3706 - 3710 (2014/04/17)
The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp3 C-H bond functionalization process. The reaction favors predominantly the C-H bonds of β-methyl groups over the unactivated methylene C-H bonds. Moreover, a preference for activating sp3 C-H bonds of β-methyl groups, via a five-membered ring intermediate, over the aromatic sp2 C-H bonds was also observed in the cyclometalation step. Additionally, sp3 C-H bonds of unactivated secondary sp3 C-H bonds could be functionalized by favoring the ring carbon atoms over the linear carbon atoms. Getting ahead on tams: The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp 3 C-H bond functionalization process to deliver β-lactams. The reaction favors the C-H bonds of β-methyl groups over the unactivated methylene C-H bonds, as well as aromatic C(sp2)-H bonds and unactivated secondary C(sp3)-H bonds of rings.
DYE COMPOUND, METHOD OF PRODUCING DIPYRROMETHENE METAL COMPLEX COMPOUND, METHOD OF PRODUCING DYE MULTIMER, SUBSTITUTED PYRROLE COMPOUND, COLORED CURABLE COMPOSITION, COLOR FILTER, METHOD OF PRODUCING COLOR FILTER, SOLID-STATE IMAGE SENSOR AND LIQUID CRYSTAL DISPLAY DEVICE
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Page/Page column 174-175, (2012/02/05)
The invention provides a dye compound having a partial structure represented by the following formula (5): wherein in formula (5), Dye represents a dye structure; G1 represents NR or an oxygen atom; G2 represents a monovalent substituent group having an -Es' value as a steric parameter of 1.5 or more; p represents an integer from 1 to 8; when p is 2 or greater, the two or more structures represented by p may be the same or different from each other; and R represents a hydrogen atom or a monovalent substituent group.
Total synthesis and structural verification of some novel branched alkanes with quaternary carbons isolated from diverse geological sources
Crich, David,Xu, Huadong,Kenig, Fabien
, p. 5016 - 5019 (2007/10/03)
With a view to the authentication of an unusual series of branched alkanes with quaternary centers (BAQCs) isolated from geological samples, and whose structures rest on the interpretation of EI-mass spectral fragmentation patterns, the total synthesis of 3-ethyl-3-methylheptadecane, 3,3-dimethylheptadecane, 3,3,11,11-tetraethyltridecane, and 5,5,7,7- tetraethylundecane is described. The GC-MS data of the first two samples are identical with those of the isolates and confirm their structures. However, the GC-MS data of the two more highly branched structures do not match those of the geological isolates leading to the conclusion that these structures were erroneously assigned.
HIGHLY SELECTIVE SYNTHESIS OF ACYCLIC TERT-ALIPHATIC CARBOXYLIC ACIDS FROM ACYCLIC TERT-ALCOHOLS USING SULFURIC ACID SUPERSATURATED WITH CARBON MONOXIDE
Takahashi, Yukio,Yoneda, Norihiko
, p. 1945 - 1954 (2007/10/02)
The selective carboxylation of acyclic tert-aliphatic alcohols was successfully performed to produce the corresponding acyclic tert-aliphatic carboxylic acids in significantly high yields using concentrated sufuric acid supersaturated with carbon monoxide.
Dipole-Stabilized Carbanions: The α' Lithiation of Piperidides
Beak, Peter,Zajdel, William J.
, p. 1010 - 1018 (2007/10/02)
The α' lithiations and subsequent electrophilic substitutions of two series of piperidides are reported.In the cases of 2,4,6-triisopropylbenzopiperidide (5) and 4-tert-butyl-2,4,6-triisopropylbenzopiperidide (6) lithiations and electrophilic substitutions give α'-substituted products, as shown in Table I, which cannot be cleaved. 2,2-Diethylbutanopiperidide (19), 4-phenyl-2,2-diethylbutanopiperidide (20), and N,N-diethyl-2,2-diethylbutanamide (18) undergo α' lithiation and electrophilic substitution as shown in Table II to give products that can be cleaved to the substituted amines.This sequence thus provides the (α-lithioalkyl)alkylamine synthetic equivalent from secondary amines.The addition of the α'-lithiated piperidides from 20 to aldehydes is shown to provide equatorial substitution with erythro and threo isomers of the amido alcohol 31 produced in a 1:1 ratio.Exclusive conversion to an equatorial threo amino ester 36t is observed on treatment with strong acid.All four possible equatorial-axial and erythro-threo isomers of the amino alcohol 34 can be obtained by appropriate manipulations.The formation of the equatorially substituted products from 6 and 20 and of syn products from N,N-diethyl-2,4,6-triisopropylbenzamide (4) is noted to be consistent with oxygen-lithium complexation and dipole stabilization as important factors in α' lithiation.
