Development of highly electron-deficient and less sterically-hindered phosphine ligands possessing 1,3,5-triazinyl groups

2018 ◽  
Vol 445 ◽  
pp. 87-93 ◽  
Author(s):  
Kazumi Abe ◽  
Masanori Kitamura ◽  
Hikaru Fujita ◽  
Munetaka Kunishima
Keyword(s):  
Phosphine Ligands ◽  
Sterically Hindered

Facile Assembly of Carbazolyl-Derived Phosphine Ligands and Their Applications in Palladium-Catalyzed Sterically Hindered Arylation Processes

2019 ◽  
Vol 23 (8) ◽  
pp. 1602-1609
Author(s):  
Man Pan Leung ◽  
Pui Ying Choy ◽  
Wing In Lai ◽  
Kin Boon Gan ◽  
Fuk Yee Kwong
Keyword(s):  
Phosphine Ligands ◽  
Palladium Catalyzed ◽  
Sterically Hindered

scholarly journals Crystal structure of the RuPhos ligand

2021 ◽  
Vol 77 (2) ◽  
pp. 171-174
Author(s):  
Kurtis M. Carsch ◽  
William Ho ◽  
Kai Hin Lui ◽  
Gregory Valtierra ◽  
Dilek K. Dogutan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Cross Coupling ◽  
Phosphine Ligands ◽  
Aryl Halides ◽  
High Catalytic Activity ◽  
State Structure ◽  
Independent Molecules ◽  
Sterically Hindered ◽  
First Time ◽  
Hindered Amines

Palladium 2-dicyclohexylphosphanyl-2′,6′-diisopropoxybiphenyl (Pd–RuPhos) catalysts demonstrate high catalytic activity for Negishi cross-couplings of sterically hindered aryl halides, for Suzuki–Miyaura cross-couplings of tosylated olefins, and for Buchwald–Hartwig amination of sterically hindered amines. The solid-state structure of the free RuPhos ligand, C30H43O2P, is reported herein for the first time. RuPhos crystallizes in a triclinic cell containing two independent molecules of the phosphine without any lattice solvent. Pertinent bond metrics and comparisons to other phosphine ligands are presented. The structure of RuPhos will be of assistance in the use of this ligand in the design of cross-coupling catalysts.

Sterically Hindered Amination of Aryl Chlorides Catalyzed by a New Carbazolyl-Derived P,N-Ligand-Composed Palladium Complex

Synthesis ◽  
2019 ◽  
Vol 51 (13) ◽  
pp. 2678-2686 ◽  
Author(s):  
Wing In Lai ◽  
Man Pan Leung ◽  
Pui Ying Choy ◽  
Fuk Yee Kwong
Keyword(s):  
Palladium Complex ◽  
Phosphine Ligand ◽  
Phosphine Ligands ◽  
Aryl Chlorides ◽  
Product Yields ◽  
Coupling Product ◽  
Remarkable Result ◽  
Sterically Hindered ◽  
Decomposition Pathway

A family of 2-(9H-carbazol-9-yl)phenyl-based phosphine ligands were synthesized and their efficacy in promoting the steric hindered Buchwald–Hartwig amination was evaluated. In the presence of Pd(OAc)2 (0.03–1.0 mol%) associated with the newly developed a carbazolyl-derived phosphine ligand, the synthesis of tetra-ortho-substituted diarylamines proceeded smoothly with excellent product yields (up to 99%). A remarkable result was obtained even for the coupling of highly sterically congested 2,6-diisopropylaniline and hindered 2-chloro-1,3,5-triisopropylbenzene (96% isolated yield). A possible decomposition pathway for the anthracenyl C–N coupling product is also reported.

Nickel-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Hydrazones

2019 ◽  
Author(s):  
Leiyang Lv ◽  
Dianhu Zhu ◽  
Zihang Qiu ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Catalytic Method ◽  
Unsaturated Hydrocarbons ◽  
Carbon Nucleophiles ◽  
Aryl Aldehydes ◽  
Aldehydes And Ketones ◽  
Sterically Hindered

Hydroalkylation of unsaturated hydrocarbons with unstablized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydroalkylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acted as both the sources of unstabilized carbanions and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a novel and reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.

Synthesis of Conjugated Triynes via Alkyne Metathesis

2019 ◽  
Author(s):  
Idriss Curbet ◽  
Sophie Colombel-Rouen ◽  
Romane Manguin ◽  
Anthony Clermont ◽  
Alexandre Quelhas ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
High Selectivity ◽  
Alkyne Metathesis ◽  
Cross Metathesis ◽  
Synthetic Strategy ◽  
Sterically Hindered ◽  
Site Selective

<div> <div> <div> <div> <p>The synthesis of conjugated triynes by molybdenum-catalyzed alkyne metathesis is reported. Strategic to the success of this approach is the utilization of sterically-hindered diynes that allowed for the site- selective alkyne metathesis to produce the desired con- jugated triyne products. The steric hindrance of alkyne moiety was found to be crucial in preventing the for- mation of diyne byproducts. This novel synthetic strategy was amenable to self- and cross-metathesis providing straightforward access to the corresponding symmetrical and dissymmetrical triynes with high selectivity. </p> </div> </div> </div> </div>

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