A Novel Access to Tertiary and Secondary ortho-Aminophenylphosphines by Protected Group Synthesis and Palladium Catalyzed P-C Coupling Reactions

2001 ◽  
Vol 56 (4-5) ◽  
pp. 347-353 ◽  
Author(s):  
Antonella Heßler ◽  
Konstantin W. Kottsieper ◽  
Stefan Schenk ◽  
Michael Tepper ◽  
Othmar Stelzer
Keyword(s):  
Coupling Reaction ◽  
Secondary Phosphine ◽  
Coupling Reactions ◽  
The Novel ◽  
Protected Group ◽  
Metallic Lithium ◽  
Subsequent Hydrolysis ◽  
Palladium Catalyzed ◽  
High Yields

Abstract The dilithium salt 1a formed by ortho-metallation of N-tert-butoxycarbonylaniline (BOC-aniline) 1 with two equivalents of tert-butyllithium reacts with the chlorophosphines Ph3-nPCln (n = 1 -3) to yield the BOC protected ortho-aminophenylphosphines 2 - 4 in high yields. On deprotection of 2 - 4 with trimethylchlorosilane in the presence of phenol the HCl adducts of the ortho-aminophenylphosphines 5 -7 are formed which may be deprotonated with KOH or NaOH to give the neutral phosphines 5a -7a. The novel secondary phosphine 8 with two ortho-aminophenyl groups is accessible by cleavage of the P-C bond in 7a with metallic lithium and subsequent hydrolysis. The bifunctional P,N ligands 6 or 6a are alternatively accessible by Pd-catalyzed P-C coupling of ortho-iodoaniline with phenylphosphine. If a 1:1 stoichiometry is employed in the coupling reaction of ortho-iodoaniline and phenylphosphine the chiral secondary phosphine 9 is formed.

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.

Ferromagnetic Chain Based on Verdazyl-Nitroxide Diradical

2020 ◽  
Author(s):  
Evgeny Tretyakov ◽  
Svetlana Zhivetyeva ◽  
Pavel Petunin ◽  
Dmitry Gorbunov ◽  
Nina Gritsan ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Ferromagnetic Coupling ◽  
Nitronyl Nitroxide ◽  
Triplet Ground State ◽  
One Dimensional ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
Ferromagnetic Chain ◽  
High Yields

<p>Verdazyl-nitroxide diradicals were synthesized using the palladium-catalyzed cross-coupling reaction of the corresponding iodoverdazyls with a nitronyl nitroxide-2-ide gold(I) complex with high yields (up to 82%). The synthesized diradicals were found to be highly thermally stable and have a singlet (D<i>E</i><sub>ST</sub> » -64 cm<sup>–1</sup>) or triplet ground state (D<i>E</i><sub>ST</sub> ³ 25 and 100 cm<sup>–1</sup>), depending on which canonical hydrocarbon diradical type they belong to. Upon crystallization, triplet diradicals form unique one-dimensional (1D) spin <i>S</i> = 1 chains of organic diradicals with intrachain ferromagnetic coupling of <i>J</i>′/<i>k</i><sub>B</sub> from 3 to 6 K.</p>

An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Radical Intermediates ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Boronic Esters ◽  
Carbon Centered Radical ◽  
Iron Based ◽  
High Yields

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.

Palladium Catalyzed Synthesis of Phenylquinoxaline-Alkyne Derivatives via Sonogashira Cross Coupling Reaction

2021 ◽  
Vol 43 (1) ◽  
pp. 95-95
Author(s):  
Rifhat Bibi Rifhat Bibi ◽  
Muhammad Yaseen Muhammad Yaseen ◽  
Haseen Ahmad Haseen Ahmad ◽  
Ismat Ullah Khan Ismat Ullah Khan ◽  
Shaista Parveen Shaista Parveen ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Sonogashira Reaction ◽  
Terminal Alkynes ◽  
Vinyl Halides ◽  
Sonogashira Coupling Reaction ◽  
Quinoxaline Derivatives ◽  
Palladium Catalyzed ◽  
High Yields ◽  
Alkyne Derivatives

Transition metals mediated cross coupling methodologies provide an extremely powerful versatile pathway in organic syntheses undoubtedly, a facile route for syntheses and derivatization of biologically important heterocycles from easily available precursors. Sonogashira coupling reaction, a leading method to Csp-Csp2 bond formation is one of the most important and rapid pathways to couple aryl/vinyl halides with terminal alkynes. Current research study deals with the synthesis of alkyne substituted quinoxaline derivatives. The quinoxalines class of aromatic heterocycles exhibits a wide variety of important biological potencies. Palladium catalyzed cross coupling process provided an effective synthetic practice for the synthesis of alkyne derivatives of quinoxaline. Vareity of terminal alkynes were coupled with 2-(4-bromophenyl)quinoxaline under optimized conditions for Sonogashira reaction, affording alkyne substituted quinoxaline derivatives in high yields. The optimized reaction conditions for coupling of range of terminal alkyne with quinoxaline basic core render this process significant for designing of medicinally interesting precursors.

scholarly journals Palladium-catalyzed Suzuki-Miyaura coupling of thioureas or thioamides

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaoyu Mai ◽  
Wendong Li ◽  
Xue Li ◽  
Yingwei Zhao ◽  
Qiuling Song
Keyword(s):  
Silver Salt ◽  
Coupling Reaction ◽  
Coupling Reactions ◽  
Mechanistic Studies ◽  
Aromatic Rings ◽  
Cross Coupling Reactions ◽  
Broad Array ◽  
Palladium Catalyzed

AbstractCross-coupling reactions involving metal carbene intermediates play an increasingly important role in C–C bond formation. Expanding the carbene precursors to a broader range of starting materials and more diverse products is an ongoing challenge in synthetic organic chemistry. Herein, we report a Suzuki-Miyaura coupling reaction of in situ-generated Pd–carbene complexes via desulfurization of thioureas or thioamides. This strategy enables the preparation of a broad array of substituted amidinium salts and unsymmetrical diaryl ketones. The reaction is readily scalable, compatible with bromo groups on aromatic rings, tolerant to moisture and air and has a broad substrate scope. Furthermore, a single crystal structure of Pd-diaminocarbene complex is obtained and proven to be the key intermediate in both catalytic and stoichiometric reactions. Preliminary mechanistic studies demonstrate the dual role of the silver salt as a desulfurating reagent assisting the elimination of sulfur and as oxidant facilitating the PdII/Pd0/PdII catalytic cycle.

The Synthesis of Novel Oligomer 4,8-Di(4-hexyl-2-thienyl)-2λ4δ2-Benzo[1,2-c;4,5-c’]bis[1,2,5]-Thiadiazole

2012 ◽  
Vol 602-604 ◽  
pp. 696-699
Author(s):  
Xiao Xiao Zhuang ◽  
Xiao Long Lei ◽  
Xiao Xia Sun
Keyword(s):  
Side Chains ◽  
Coupling Reactions ◽  
Low Bandgap ◽  
Palladium Catalyzed ◽  
Efficient Route ◽  
High Yields ◽  
Bandgap Materials

Heterocyclic oligomer based on BBT bearing solubilizing side chains have been synthesized in high yields over six steps from readily available starting materials. This approach offers a much milder, shorter, and more efficient route to BBT derivatives than current methods. This unit can then be used in the synthesis of low bandgap materials via palladium-catalyzed coupling reactions.

Palladium-catalyzed dehydrogenative coupling of terminal alkynes with secondary phosphine oxides

2015 ◽  
Vol 51 (17) ◽  
pp. 3549-3551 ◽  
Author(s):  
Jia Yang ◽  
Tieqiao Chen ◽  
Yongbo Zhou ◽  
Shuangfeng Yin ◽  
Li-Biao Han
Keyword(s):  
Reaction Mechanism ◽  
Palladium Acetate ◽  
Secondary Phosphine ◽  
Terminal Alkynes ◽  
Phosphine Oxides ◽  
Dehydrogenative Coupling ◽  
Palladium Catalyzed ◽  
High Yields

The palladium-catalyzed dehydrogenative coupling of alkynes with secondary phosphine oxides is developed. Thus, in the presence of a silver additive, palladium acetate could efficiently catalyze the dehydrocoupling of secondary phosphine oxides with a variety of alkynes to produce the corresponding alkynylphosphine oxides in high yields. A reaction mechanism is proposed.

Synthesis of 5- and 6-Azaindoles by Sequential Site-Selective Palladium-Catalyzed C–C and C–N Coupling Reactions

Synlett ◽  
2020 ◽  
Vol 31 (13) ◽  
pp. 1308-1312
Author(s):  
Tuan Thanh Dang ◽  
Peter Langer ◽  
Nguyen Thi Son ◽  
Tuan Anh Nguyen Tien ◽  
Marian Blanco Ponce ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
The Other ◽  
Sonogashira Reaction ◽  
Coupling Reactions ◽  
Other Hand ◽  
Sequential Procedures ◽  
Palladium Catalyzed ◽  
A Site ◽  
Site Selective

Two-step sequential procedures for the Pd-catalyzed synthesis of 5- and 6-azaindoles are reported. The reactions proceed in very good yields. 6-Azaindoles are formed through site-selective Pd-catalyzed Sonogashira reaction of 3,4-dibromopyridine with alkynes, followed by a Pd-catalyzed tandem C–N coupling and cyclization with amines. On the other hand, 5-azaindoles are obtained by a site-selective Pd-catalyzed C–N coupling reaction of 3,4-dibromopyridine with amines, followed by C–C coupling and cyclization with alkynes.

scholarly journals Regioselective Synthesis of New 2,4-(Het)aryl-3H-pyrido[1′,2′:1,5]pyrazolo[4,3-d]pyrimidines Involving Palladium-Catalyzed Cross-Coupling Reactions

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2740 ◽  
Author(s):  
Abdelaziz Ejjoummany ◽  
Rabia Belaroussi ◽  
Ahmed El Hakmaoui ◽  
Mohamed Akssira ◽  
Gérald Guillaumet ◽  
...  
Keyword(s):  
Process Optimization ◽  
Cross Coupling ◽  
Regioselective Synthesis ◽  
Coupling Reactions ◽  
Pyrimidine Derivatives ◽  
Release Process ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
High Yields

The design of some novel di-(het)arylated-3H-pyrido[1′,2′:1,5]pyrazolo[4,3-d]pyrimidine derivatives is reported. The series was developed from 1-aminopyridinium iodide, which afforded the key intermediate bearing two thiomethyl and amide functions, each of them useful for palladium catalyzed cross coupling reactions by alkyl sulfur release and C-O activation, respectively. The two regioselective and successive cross-coupling reactions were first carried out in C-4 by in situ C-O activation and next in C-2 by a methylsulfur release. Process optimization furnished conditions leading to products in high yields. The scope and limitations of the methodologies were evaluated and the final compounds characterized.

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