scholarly journals Palladium-Catalyzed Cross-Coupling of Gem-Bromofluoroalkenes with Alkylboronic Acids for the Synthesis of Alkylated Monofluoroalkenes

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5532
Author(s):  
Laëtitia Chausset-Boissarie ◽  
Nicolas Cheval ◽  
Christian Rolando
Keyword(s):  
Organic Synthesis ◽  
Functional Group ◽  
Materials Science ◽  
Cross Coupling ◽  
High Yield ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Strategy

Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of gem-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the gem-bromofluoroalkenes geometry.

Lewis Acid-Mediated Efficient Synthesis of 4H-1,3-benzo-xazines and Their Derivatives 4,5-dihydro-1,3-benzo-xazepines

2020 ◽  
Vol 24 (11) ◽  
pp. 1263-1273
Author(s):  
An Junkai ◽  
Liu Jikun ◽  
Shi Ying ◽  
Zhu Weiwei ◽  
Guo Guoying ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Lewis Acid ◽  
Functional Group ◽  
Materials Science ◽  
Pharmaceutical Research ◽  
Direct Access ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Promising Strategy ◽  
Characteristic Features

: Compounds containing 4H-1,3-benzo-xazine core usually possess characteristic features and have been applied in the fields of organic synthesis, pharmaceutical research, materials science and bioscience. Here we reported convenient and direct access to 4H-1,3- benzo-xazines and their derivatives through intramolecular cyclization of olefinic amides or ureas with good to excellent yields in the presence of TMSOTf. The properties (mild conditions, metal or additives-free, wide substrate scope and functional group tolerance) of the process made it a promising strategy to synthesize various benzo-xazines and their derivatives.

scholarly journals Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

2019 ◽  
Author(s):  
Van Tran ◽  
Zi-Qi Li ◽  
Timothy Gallagher ◽  
Joseph Derosa ◽  
Peng Liu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Cross Coupling ◽  
Building Blocks ◽  
Reductive Elimination ◽  
Mechanistic Studies ◽  
Mild Conditions ◽  
Wide Range ◽  
Directing Group ◽  
Weakly Coordinating ◽  
Analogous Method

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate azaheterocycle directing groups, that useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated in the facile reactivity of the β-γ alkene of the starting material, while the ε-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of analogous method with alkyne substrates. Mechanistic studies reveal the importance of the weakly coordinating directing group in dissociating to allow binding of the allyl moiety to facilitate C(sp<sup>3</sup>)–C(sp<sup>3</sup>) reductive elimination.

scholarly journals Integrating Allyl Electrophiles into Nickel-Catalyzed Conjunctive Cross-Coupling

2019 ◽  
Author(s):  
Van Tran ◽  
Zi-Qi Li ◽  
Timothy Gallagher ◽  
Joseph Derosa ◽  
Peng Liu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Cross Coupling ◽  
Building Blocks ◽  
Reductive Elimination ◽  
Mechanistic Studies ◽  
Mild Conditions ◽  
Wide Range ◽  
Directing Group ◽  
Weakly Coordinating ◽  
Analogous Method

Allylation and conjunctive cross-coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel-catalyzed conjunctive cross-coupling with a non-conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate azaheterocycle directing groups, that useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated in the facile reactivity of the β-γ alkene of the starting material, while the ε-ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of analogous method with alkyne substrates. Mechanistic studies reveal the importance of the weakly coordinating directing group in dissociating to allow binding of the allyl moiety to facilitate C(sp<sup>3</sup>)–C(sp<sup>3</sup>) reductive elimination.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

scholarly journals Photocatalytic three-component asymmetric sulfonylation via direct C(sp3)-H functionalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shi Cao ◽  
Wei Hong ◽  
Ziqi Ye ◽  
Lei Gong
Keyword(s):  
Asymmetric Catalysis ◽  
Organic Synthesis ◽  
Photochemical Reaction ◽  
Low Cost ◽  
Bioactive Molecules ◽  
Atom Economy ◽  
Mild Conditions ◽  
Wide Range ◽  
Unsaturated Carbonyl Compound ◽  
Direct Functionalization

AbstractThe direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (>50 examples, up to >50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides an appealing access to enantioenriched compounds starting from the abundant hydrocarbon compounds.

Bromotrifluoromethane: A Useful Reagent for Hydrotrifluoromethylation of Alkenes and Alkynes

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1028-1032 ◽  
Author(s):  
Xing Zheng ◽  
Xingang Zhang ◽  
Yu-Yan Ren
Keyword(s):  
Visible Light ◽  
Organic Synthesis ◽  
Functional Group ◽  
Mild Conditions ◽  
Industrial Material ◽  
Reaction Proceeds

Bromotrifluoromethane (CF3Br) is a simple, inexpensive and abundant industrial material employed as a trifluoromethylating reagent. However, only limited strategies using CF3Br as a fluorine source are reported. Herein, we describe a visible-light-induced hydrotrifluoromethylation of alkenes and alkynes with CF3Br. The reaction proceeds under mild conditions with good functional group tolerance, providing a new route for the application of BrCF3 in organic synthesis.

Stereodivergent Hydrosilylation, Hydrostannylation, and Hydrogermylation of α-Trifluoromethylated Alkynes and Their Synthetic Applications

Synthesis ◽  
2016 ◽  
Vol 48 (19) ◽  
pp. 3317-3330 ◽  
Author(s):  
Cédric Tresse ◽  
Stéphane Schweizer ◽  
Philippe Bisseret ◽  
Jacques Lalevée ◽  
Gwilherm Evano ◽  
...  
Keyword(s):  
Functional Group ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

Stereoselective hydrometalation reactions of aryl- and alkyl-substituted trifluoromethylated alkynes with triethylsilane, tributylstannane, and triphenylgermane have been investigated. (E)-α-CF3-Vinylsilanes, -stannanes, and -germanes were obtained under palladium-catalyzed conditions whereas the corresponding (Z)-α-CF3-vinylgermanes were obtained under radical conditions. These reactions proceed in good to excellent yields and possess a broad functional group tolerance. Applications of the (Z)- and (E)-α-CF3-vinylgermanes in palladium-catalyzed cross-coupling reactions with aryl halides having diverse electronic requirements were also investigated. The corresponding (Z)- and (E)-α-CF3-styrenes were obtained as single isomers, thus demonstrating the utility of these versatile synthons for the synthesis of stereodefined trifluoromethylated alkenes.

Efficient symmetrical bidentate dioxime ligand-accelerated homogeneous palladium-catalyzed Suzuki–Miyaura coupling reactions of aryl chlorides

2017 ◽  
Vol 41 (1) ◽  
pp. 372-376 ◽  
Author(s):  
Jinyi Song ◽  
Hongyan Zhao ◽  
Yang Liu ◽  
Huatao Han ◽  
Zhuofei Li ◽  
...  
Keyword(s):  
High Activity ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Bidentate Ligands ◽  
Aryl Chlorides ◽  
Arylboronic Acids ◽  
Mild Conditions ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

A series of N,O-bidentate ligands were synthesized and studied as high activity ligands for palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids under mild conditions.

scholarly journals Nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts enabled by NN2 pincer ligand

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingjie Zhang ◽  
Di Qi ◽  
Chenchen Jiao ◽  
Xiaopan Liu ◽  
Guisheng Zhang
Keyword(s):  
Functional Group ◽  
High Efficiency ◽  
Materials Science ◽  
Alkylating Agents ◽  
Sonogashira Coupling ◽  
Pincer Ligand ◽  
One Pot ◽  
Mild Conditions ◽  
Alkyl Amines ◽  
Sonogashira Reactions

AbstractAlkynes are amongst the most valuable functional groups in organic chemistry and widely used in chemical biology, pharmacy, and materials science. However, the preparation of alkyl-substituted alkynes still remains elusive. Here, we show a nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts. Key to the success of this coupling is the development of an easily accessible and bench-stable amide-type pincer ligand. This ligand allows naturally abundant alkyl amines as alkylating agents in Sonogashira reactions, and produces diverse alkynes in excellent yields under mild conditions. Salient merits of this chemistry include broad substrate scope and functional group tolerance, gram-scale synthesis, one-pot transformation, versatile late-stage derivatizations as well as the use of inexpensive pre-catalyst and readily available substrates. The high efficiency and strong practicability bode well for the widespread applications of this strategy in constructing functional molecules, materials, and fine chemicals.

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