Category: 13788-92-6

McCann, Scott D.; Reichert, Elaine C.; Arrechea, Pedro Luis; Buchwald, Stephen L. published the artcile< Development of an Aryl Amination Catalyst with Broad Scope Guided by Consideration of Catalyst Stability>, Electric Literature of 13788-92-6, the main research area is dialkylbiaryl monosphosphine ligand preparation amination coupling catalyst.

The authors have developed a new dialkylbiaryl monophosphine ligand, GPhos, that supports a palladium catalyst capable of promoting carbon-nitrogen cross-coupling reactions between a variety of primary amines and aryl halides; in many cases, these reactions can be carried out at room temperature The reaction development was guided by the idea that the productivity of catalysts employing BrettPhos-like ligands is limited by their lack of stability at room temperature Specifically, it was hypothesized that primary amine and N-heteroaromatic substrates can displace the phosphine ligand, leading to the formation of catalytically dormant palladium complexes that reactivate only upon heating. This notion was supported by the synthesis and kinetic study of a putative off-cycle Pd complex. Consideration of this off-cycle species, together with the identification of substrate classes that are not effectively coupled at room temperature using previous catalysts, led to the design of a new dialkylbiaryl monophosphine ligand. An Ot-Bu substituent was added ortho to the dialkylphosphino group of the ligand framework to improve the stability of the most active catalyst conformer. To offset the increased size of this substituent, the authors also removed the para i-Pr group of the non-phosphorus-containing ring, which allowed the catalyst to accommodate binding of even very large α-tertiary primary amine nucleophiles. In comparison to previous catalysts, the GPhos-supported catalyst exhibits better reactivity both under ambient conditions and at elevated temperatures Its use allows for the coupling of a range of amine nucleophiles, including (1) unhindered, (2) five-membered-ring N-heterocycle-containing, and (3) α-tertiary primary amines, each of which previously required a different catalyst to achieve optimal results.

Journal of the American Chemical Society published new progress about Amination. 13788-92-6 belongs to class pyrazoles-derivatives, and the molecular formula is C9H7BrN2, Electric Literature of 13788-92-6.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Tan, Yun-Xuan; Liu, Xing-Yu; Zhang, Shuo-Qing; Xie, Pei-Pei; Wang, Xin; Feng, Kai-Rui; Yang, Shao-Qian; He, Zhi-Tao; Hong, Xin; Tian, Ping; Lin, Guo-Qiang published the artcile< An unconventional trans-exo-selective cyclization of alkyne-tethered cyclohexadienones initiated by rhodium(III)-catalyzed C-H activation via insertion relay>, Computed Properties of 13788-92-6, the main research area is rhodium carbon hydrogen activation catalysis alkyne cyclohexadienone cyclization.

Different from the established trans-endo-selective cyclization of alkyne-tethered electrophiles that involve an E/Z isomerization process, herein, the authors present a novel strategy to allow trans-exo-selective arylative cyclization of 1,6-enynes. Through initiation of rhodium(III)-catalyzed C-H activation, a diverse range of N-heterocyclic directing groups, including pyridine, pyrazole, imidazo[1,2-a] pyridine, benzoxazole, benzothiazole, and purine, was feasible for the cascade transformation, exhibiting high efficiency (up to 92% yield), broad substrate scope, and excellent functional group compatibility. Moreover, the modification of natural products and pharmaceutical compounds was also demonstrated to showcase its synthetic utility. Based on d. functional theory (DFT) calculations, a key three-membered ring intermediate through the insertion relay, rather than the direct E/Z isomerization of alkenyl rhodium species, controlled the stereochem. outcome for this trans-exo-selective cyclization. The subsequent ring-opening protonation of the more favored rotamer led to exclusive trans-exo-selectivity.

CCS Chemistry published new progress about C-H bond activation. 13788-92-6 belongs to class pyrazoles-derivatives, and the molecular formula is C9H7BrN2, Computed Properties of 13788-92-6.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Liu, Haidong; Ge, Liang; Wang, Ding-Xing; Chen, Nan; Feng, Chao published the artcile< Photoredox-Coupled F-Nucleophilic Addition: Allylation of gem-Difluoroalkenes>, Safety of 1-(4-Bromophenyl)-1H-pyrazole, the main research area is homoallylic trifluoromethane preparation; gem difluoroalkene photoredox coupled fluoroallylation; allylic compounds; fluorine; photochemistry; radicals; reaction mechanisms.

A novel strategy for the expedient construction of CF3-embeded tertiary/quaternary carbon centers was developed by taking advantage of photoredox catalysis. Thanks to a key step of single-electron oxidation, electron-rich gem-difluoroalkenes, which otherwise are essentially reluctant towards F-nucleophilic addition, now readily participate in this fluoroallylation reaction. Furthermore, this strategy provides an elegant example for the generation, as well as functionalization, of α-CF3-substituted benzylic radical intermediates using cheap and readily available starting materials.

Angewandte Chemie, International Edition published new progress about Allylation (fluoro). 13788-92-6 belongs to class pyrazoles-derivatives, and the molecular formula is C9H7BrN2, Safety of 1-(4-Bromophenyl)-1H-pyrazole.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Becica, Joseph; Hruszkewycz, Damian P.; Steves, Janelle E.; Elward, Jennifer M.; Leitch, David C.; Dobereiner, Graham E. published the artcile< High-Throughput Discovery and Evaluation of a General Catalytic Method for N-Arylation of Weakly Nucleophilic Sulfonamides>, Computed Properties of 13788-92-6, the main research area is tertiary sulfonamide preparation palladium catalyst; secondary sulfonamide heteroaryl halide arylation high throughput screening.

Through targeted high-throughput experimentation (HTE), authors have identified the Pd/AdBippyPhos catalyst system as an effective and general method to construct densely functionalized N,N-diaryl sulfonamide motifs relevant to medicinal chem. AdBippyPhos is particularly effective for the installation of heteroaromatic groups. Computational steric parametrization of the investigated ligands reveals the potential importance of remote steric demand, where a large cone angle combined with an accessible Pd center is correlated to successful catalysts for C-N coupling reactions.

Organic Letters published new progress about Arenesulfonamides Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 13788-92-6 belongs to class pyrazoles-derivatives, and the molecular formula is C9H7BrN2, Computed Properties of 13788-92-6.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics