scholarly journals Understanding Site Selectivity in the Palladium-Catalyzed Cross-Coupling of Allenylsilanolates

Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2415-2420
Author(s):  
Scott Denmark ◽  
Andrea Ambrosi
Keyword(s):  
Cross Coupling ◽  
The Other ◽  
Fine Tuning ◽  
Reaction Conditions ◽  
Site Selectivity ◽  
Palladium Catalyzed ◽  
Selective Formation ◽  
Useful Yield

Allenylsilanolates can undergo cross-coupling at the α- or γ-terminus, and site selectivity appears to be determined by the intrinsic transmetalation mechanism. Fine-tuning of concentration, nucleophilicity, and steric bulk of the silanolate moiety allows for the selective formation of one isomer over the other. Whereas the α-isomer can be obtained in synthetically useful yield, the γ-isomer is favored only when employing reaction conditions that are inevitably associated with diminished reactivity.

Suzuki–Miyaura cross-coupling for chemoproteomic applications

2020 ◽  
Author(s):  
Jian Cao ◽  
Ernest Armenta ◽  
Lisa Boatner ◽  
Heta Desai ◽  
Neil Chan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cross Coupling ◽  
Protein Profiling ◽  
Protein Labeling ◽  
Caspase 8 ◽  
Complex Cell ◽  
Bioorthogonal Chemistry ◽  
Reaction Conditions ◽  
Target Deconvolution ◽  
Palladium Catalyzed

Bioorthogonal chemistry is a mainstay of chemoproteomic sample preparation workflows. While numerous transformations are now available, chemoproteomic studies still rely overwhelmingly on copper-catalyzed azide –alkyne cycloaddition (CuAAC) or 'click' chemistry. Here we demonstrate that gel-based activity-based protein profiling (ABPP) and mass-spectrometry-based chemoproteomic profiling can be conducted using Suzuki–Miyaura cross-coupling. We identify reaction conditions that proceed in complex cell lysates and find that Suzuki –Miyaura cross-coupling and CuAAC yield comparable chemoproteomic coverage. Importantly, Suzuki–Miyaura is also compatible with chemoproteomic target deconvolution, as demonstrated using structurally matched probes tailored to react with the cysteine protease caspase-8. Uniquely enabled by the observed orthogonality of palladium-catalyzed cross-coupling and CuAAC, we combine both reactions to achieve dual protein labeling.

Regiospecific Palladium-Catalyzed Cross-Coupling Reactions Using the Operational Equivalent of 1,3-Dilithiopropyne

Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2387-2394 ◽  
Author(s):  
Jorge A. Cabezas ◽  
Natasha Ferllini
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Terminal Alkyne ◽  
Copper Iodide ◽  
Reaction Conditions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
High Yields

A regiospecific palladium-catalyzed cross-coupling reaction using the operational equivalent of the dianion 1,3-dilithiopropyne, with aromatic iodides is reported. This reaction gives high yields of 1-propyn-1-yl-benzenes and 2-(propyn-1-yl)thiophenes in the presence of catalytic amounts of palladium(0) or (II) and stoichiometric amounts of copper iodide. No terminal alkyne or allene isomers were detected. Reaction conditions were very mild and several functional groups were tolerated.

scholarly journals Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

2020 ◽  
Vol 16 ◽  
pp. 1335-1342
Author(s):  
Shrikant D Tambe ◽  
Kwan Hong Min ◽  
Naeem Iqbal ◽  
Eun Jin Cho
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Aliphatic Amine ◽  
Cross Coupling ◽  
The Other ◽  
Single Electron Transfer ◽  
Reductive Coupling ◽  
Phenyl Substituent ◽  
Reaction Conditions ◽  
Judicious Choice

A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of a phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical–radical cross-coupling of α-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by the judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.

Palladium-Catalyzed C–P Cross-Coupling between (Het)aryl Halides and Secondary Phosphine Oxides

Synthesis ◽  
2019 ◽  
Vol 51 (11) ◽  
pp. 2379-2386 ◽  
Author(s):  
Gladis Zakirova ◽  
Dmitrii Mladentsev ◽  
Nataliya Borisova
Keyword(s):  
Electronic Properties ◽  
Heterocyclic Compounds ◽  
Cross Coupling ◽  
Secondary Phosphine ◽  
Phosphine Oxides ◽  
Tertiary Phosphine ◽  
Reaction Conditions ◽  
Efficient Procedure ◽  
Palladium Catalyzed ◽  
Tertiary Alkyl

An efficient procedure for C–P bond formation via the palladium-catalyzed [Pd(OAc)2/dppf/Cs2CO3] reaction between dichloroheterocycles and secondary phosphine oxides was developed. The steric and electronic properties of substituents were varied to establish the scope and limitations of the method developed. By applying these conditions, a variety of new heterocyclic compounds bearing two tertiary phosphine oxides were successfully synthesized in moderate to excellent yields. After adjustments to the reaction conditions [Pd(OAc)2/dippf/t-BuOK], cross-coupling of secondary phosphine oxides with bulky (secondary or tertiary alkyl) substituents on the phosphorus atom was achieved. Extension of the methodology to monohalohetarenes and monohaloarenes was successfully carried out; once again, the steric and electronic properties of the halides were varied widely. The desired reaction occurred in all cases studied, giving high to excellent yields of product regardless of the nature and positions of substituents.

Consecutive Palladium Catalyzed Reactions in One-Pot Reactions

2020 ◽  
Vol 17 (5) ◽  
pp. 559-569
Author(s):  
Ingrid Caroline Vaaland ◽  
Magne Olav Sydnes
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Homogeneous Reaction ◽  
Reaction Conditions ◽  
One Pot ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
Catalyzed Reactions

Combining palladium catalyzed reactions in one-pot reactions represents an efficient and economical use of catalyst. The Suzuki-Miyaura cross-coupling has been proven to be a reaction which can be combined with other palladium catalyzed reactions in the same pot. This mini-review will highlight some of the latest examples where Suzuki-Miyaura cross-coupling reactions have been combined with other palladium catalyzed reactions in one-pot reaction. Predominantly, examples with homogeneous reaction conditions will be discussed in addition to a few examples from the authors where Pd/C have been used as a catalyst.

Palladium-catalyzed cross-coupling of enamides with sterically hindered α-bromocarbonyls

2016 ◽  
Vol 52 (32) ◽  
pp. 5617-5620 ◽  
Author(s):  
Ran Ding ◽  
Zhi-Dao Huang ◽  
Zheng-Li Liu ◽  
Tian-Xiang Wang ◽  
Yun-He Xu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Alcohol ◽  
Cross Coupling ◽  
Reaction Conditions ◽  
Palladium Catalyzed ◽  
Sterically Hindered

Palladium-catalyzed intermolecular alkylation of enamides with α-bromo carbonyls was developed. Under mild reaction conditions, various cyclic and acyclic enamides reacted well with α-bromo carbonyls to afford the corresponding multi-substituted alkene products in good yields. The coupling products could be converted into very useful γ-amino acid, δ-amino alcohol, 1,4-dicarbonyl and γ-lactam derivatives.

Palladium-Catalyzed Csp3–H Bond mono-Aroyloxylation of O-Alkyl Substituted 2,4,6-Trimethoxybenzaldoxime Ethers

Synlett ◽  
2018 ◽  
Vol 29 (09) ◽  
pp. 1249-1255
Author(s):  
Wen-Li Qiao ◽  
Ling-Yan Shao ◽  
Ya-Hua Hu ◽  
Li-Hao Xing ◽  
Ke-Zuan Deng ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Aliphatic Alcohol ◽  
Cross Coupling ◽  
Aliphatic Alcohols ◽  
Aromatic Acid ◽  
Rapid Access ◽  
Site Selectivity ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group

A palladium-catalyzed Csp3–H bond mono-aroyloxylation of O-alkyl substituted oxime ethers has been developed by using 2,4,6-trimethoxybenzaldoxime as an exo-type directing group with exclusive site-selectivity. With the wide range of masked aliphatic alcohol substrates and aromatic acid coupling partners, the protocol allows rapid access to various 2-alkyl substituted glycol derivatives in synthetically useful to good yields. The employed directing group is readily removed, accordingly affording valuable functionalized aliphatic alcohols. When the solvent from hybrid DCE/HFIP to CH3CN, non-directed oxidative cross-coupling is observed between the electron-rich aromatic ring of substrates and aromatic acid partners.

Palladium-Catalyzed Cross-Coupling Reactions of 4-Tosyl­oxyquinazolines with Indoles: An Efficient Approach to 4-(1H-Indol-1-yl)quinazolines

Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 383-390 ◽  
Author(s):  
Yiyuan Peng ◽  
Xinglin Ye ◽  
Jian Huang ◽  
Zhihong Deng ◽  
Jianjun Yuan
Keyword(s):  
Late Stage ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Indole Derivatives ◽  
Reaction Conditions ◽  
Efficient Approach ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

In this paper, exploration of our continuous interests on late-stage derivation of quinozaline core is described. A wide array of 4-(1H-indol-1-yl)quinazolines were obtained in good to excellent yields through palladium-catalyzed cross-coupling of 4-tosyloxyquinazolines with indole derivatives under mild reaction conditions.

Manganese-Catalyzed Kumada Cross-Coupling Reactions of Aliphatic Grignard Reagents with N-Heterocyclic Chlorides

Synlett ◽  
2018 ◽  
Vol 29 (13) ◽  
pp. 1700-1706 ◽  
Author(s):  
Ellen Matson ◽  
Brittney Petel ◽  
Merjema Purak
Keyword(s):  
Reaction Rate ◽  
Metal Salt ◽  
Cross Coupling ◽  
Environmentally Benign ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Heterocyclic Molecules ◽  
Cross Coupling Reactions ◽  
High Yields ◽  
Selective Formation

Herein we report the use of manganese(II) chloride for the catalytic generation of C(sp2)–C(sp3) bonds via Kumada cross-coupling. Rapid and selective formation of 2-alkylated N-heterocyclic complexes were observed in high yields with use of 3 mol% MnCl2THF1.6 and under ambient reaction conditions (21 °C, 15 min to 20 h). Manganese-catalyzed cross-coupling is tolerant toward both electron-donating and electron-withdrawing functional groups in the 5-position of the pyridine ring, with the latter resulting in an increased reaction rate and a decrease in the amount of nucleophile required. The use of this biologically and environmentally benign metal salt as a catalyst for C–C bond formation highlights its potential as a catalyst for the late-stage functionalization of pharmaceutically active N-heterocyclic molecules (e.g., pyridine, pyrazine).

scholarly journals Structural Identification between Phthalazine-1,4-Diones and N-Aminophthalimides via Vilsmeier Reaction: Nitrogen Cyclization and Tautomerization Study

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2907
Author(s):  
Cheng-Yen Chung ◽  
Ching-Chun Tseng ◽  
Sin-Min Li ◽  
Shuo-En Tsai ◽  
Hui-Yi Lin ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Structural Identification ◽  
Experimental Results ◽  
The Other ◽  
Vilsmeier Reaction ◽  
Cyclization Reactions ◽  
Reaction Conditions ◽  
Other Hand ◽  
Structural Divergence ◽  
Selective Formation

N-aminophthalimides and phthalazine 1,4-diones were synthesized from isobenzofuran-1,3-dione, isoindoline-1,3-dione, furo [3,4-b] pyrazine-5,7-dione, or 1H-pyrrolo [3,4-c] pyridine-1,3-dione with monohydrate hydrazine to carry out the 5-exo or 6-endo nitrogen cyclization under the different reaction conditions. Based on the control experimental results, 6-endo thermodynamic hydrohydrazination and kinetical 5-exo cyclization reactions were individually selective formation. Subsequently, Vilsmeier amidination derivatization was successfully developed to probe the structural divergence between N-aminophthalimide 2 and phthalazine 1,4-dione 3. On the other hand, the best tautomerization of N-aminophthalimide to diazinone was also determined under acetic acid mediated solution.

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