78238-99-0Relevant academic research and scientific papers
Synthesis of Triarylmethanes via Palladium-Catalyzed Suzuki Coupling of Trimethylammonium Salts and Arylboronic Acids
Zhang, Zhenming,Wang, Hui,Qiu, Nianli,Kong, Yujing,Zeng, Wenjuan,Zhang, Yongquan,Zhao, Junfeng
, p. 8710 - 8715 (2018/07/21)
An efficient palladium-catalyzed Suzuki coupling of 1,1-diarylmethyl-trimethylammonium triflates with arylboronic acids is reported. This reaction offers a novel approach to triarylmethane derivatives in good to excellent yields with the palladium-catalyzed C-N bond cleavage as the key feature. Broad substrate scope regarding both reaction partners are observed. Moreover, reactive functional groups such as vinyl and formyl groups are conserved in this transformation.
Cine Substitution with Arylzinc Reagents: Scope and Mechanistic Studies
Barroso, Santiago,Lemaire, Sébastien,Farina, Vittorio,Steib, Andreas K.,Blanc, Romain,Knochel, Paul
, p. 2804 - 2816 (2016/04/26)
The unexpected ability of arylzinc reagents bearing electron-donating substituents to react in a Friedel-Crafts fashion (cine) with electrophiles like perpivaloylated glucoside bromide and benzhydryl bromides in competition with organometallic coupling (ipso) is shown. The stereoelectronic factors required to promote the cine reactivity versus the classical ipso, and the mechanism of this alternative pathway, have been investigated. The Wheland intermediate is deprotonated intramolecularly in a 1,2-shift but also in a longer-range shift, leaving in this case the C-Zn untouched. In the latter case, it is possible to take advantage of this result for further functionalization.
LDA-Mediated Synthesis of Triarylmethanes by Arylation of Diarylmethanes with Fluoroarenes at Room Temperature
Ji, Xinfei,Huang, Tao,Wu, Wei,Liang, Fang,Cao, Song
supporting information, p. 5096 - 5099 (2015/11/03)
A practical and convenient approach for the secondary C(sp3)-H arylation of diarylmethanes with various fluoroarenes is described. The reaction proceeds smoothly in the presence of LDA (lithium diisopropylamide) at room temperature and affords triarylmethanes in moderate to high yields.
Cu-Catalyzed Suzuki-Miyaura reactions of primary and secondary benzyl halides with arylboronates
Sun, Yan-Yan,Yi, Jun,Lu, Xi,Zhang, Zhen-Qi,Xiao, Bin,Fu, Yao
, p. 11060 - 11062 (2014/09/30)
A copper-catalyzed Suzuki-Miyaura coupling of benzyl halides with arylboronates is described. Varieties of primary benzyl halides as well as more challenging secondary benzyl halides with β hydrogens or steric hindrance could be successfully converted into the corresponding products. Thus it provides access to diarylmethanes, diarylethanes and triarylmethanes. This journal is the Partner Organisations 2014.
Palladium-catalyzed C(sp3)-H arylation of diarylmethanes at room temperature: Synthesis of triarylmethanes via deprotonative-cross-coupling processes
Zhang, Jiadi,Bellomo, Ana,Creamer, Andrea D.,Dreher, Spencer D.,Walsh, Patrick J.
supporting information; experimental part, p. 13765 - 13772 (2012/10/08)
Although metal-catalyzed direct arylation reactions of non- or weakly acidic C-H bonds have recently received much attention, chemists have relied heavily on substrates with appropriately placed directing groups to steer reactivity. To date, examples of intermolecular arylation of unactivated C(sp3)-H bonds in the absence of a directing group remain scarce. We report herein the first general, high-yielding, and scalable method for palladium-catalyzed C(sp3)-H arylation of simple diarylmethane derivatives with aryl bromides at room temperature. This method facilitates access to a variety of sterically and electronically diverse hetero- and nonheteroaryl-containing triarylmethanes, a class of compounds with various applications and interesting biological activity. Key to the success of this approach is an in situ metalation of the substrate via C-H deprotonation under catalytic cross-coupling conditions, which is referred to as a deprotonative-cross-coupling process (DCCP). Base and catalyst identification were performed by high-throughput experimentation (HTE) and led to a unique base/catalyst combination [KN(SiMe3)2/Pd-NiXantphos] that proved to efficiently promote the room-temperature DCCP of diarylmethanes. Additionally, the DCCP exhibits remarkable chemoselectivity in the presence of substrates that are known to undergo O-, N-, enolate-, and C(sp2)-H arylation.
Anomalous Acetoxylation of Aromatic Nuclei: Some Structural Requirements in the Substrate
Bandaranayake, Wickramasinghe M.,Riggs, Noel V.
, p. 115 - 129 (2007/10/02)
For certain aromatic nuclei, bromination in acetic acid in the presence of pyridine is accompanied by nuclear acetoxylation.As first observed with galbulin, when two alkoxyl groups, one meta and one para to a benzylic centre of the substrate are present, acetoxylation occurs at the intervening ortho position.Under the given conditions, acetoxylation occurs at position 8 of 6,7-dimethoxy-1-phenyl-1,2,3,4-tetrahydronaphthalene, and at position 2 of 3,4-dimethoxy diphenyl and triphenyl-methanes.Acetoxylation does not occur in the absence of either of the alkoxy groups or in the absence of pyridine, not does it occur in the pendant ring of 1-(3',4'-dimethoxyphenyl)-1,2,3,4-tetrahydronaphthalene.These results are consistent with the earlier suggestion that the reaction occurs by way of initial oxidative formation of a doubly benzylic cation
