35664-71-2Relevant academic research and scientific papers
Zinc-gold cooperative catalysis for the direct alkynylation of benzofurans
Li, Yifan,Waser, Jerome
, p. 1763 - 1767 (2013)
The direct alkynylation of benzofurans was achieved for the first time using the hypervalent iodine reagent 1-[(triiso-propylsilyl)ethynyl]-1,2- benziodoxol-3(1H)-one (TIPS-EBX) based on the cooperative effect between a gold catalyst and a zinc Lewis acid. High selectivity was observed for C2-alkynylation of benzofurans substituted with alkyl, aryl, halogen and ether groups. The reaction was also successful in the case of the more complex drug 8-methoxypsoralen (8-MOP).
The Hiyama Cross-Coupling Reaction at Parts Per Million Levels of Pd: In Situ Formation of Highly Active Spirosilicates in Glycol Solvents
Ichii, Shun,Hamasaka, Go,Uozumi, Yasuhiro
supporting information, p. 3850 - 3854 (2019/11/11)
A palladium NNC-pincer complex at a 5 mol ppm loading efficiently catalyzed the Hiyama coupling reaction of aryl bromides with aryl(trialkoxy)silanes in propylene glycol to give the corresponding biaryls in excellent yields. This method was applied to the syntheses of adapalene and a biaryl-type liquid-crystalline compound, as well as to the derivatization of dextromethorphan and norfloxacin. ESI-MS and NMR analyses of the reaction mixture suggested the formation of pentacoordinate spirosilicate intermediates in situ. Preliminary theoretical studies revealed that the glycol-derived silicate intermediates formed in situ are quite reactive silicon reagents in the transmetalation step.
Dioxazolones as masked ester surrogates in the Pd(ii)-catalyzed direct C-H arylation of 6,5-fused heterocycles
Saxena, Paridhi,Maida, Neha,Kapur, Manmohan
, p. 11187 - 11190 (2019/09/30)
A simple and effective Pd(ii)-catalyzed regioselective C(2)-H arylation of 6,5-fused heterocycles with dioxazolones as a masked ester surrogate under mild conditions is reported. The significance of the arylation is highlighted by the new reactivity demonstrated in dioxazolones via proximal C-H activation of the cyclic carbonate of the hydroxamic acid functionality under protic conditions.
Direct Dimesitylborylation of Benzofuran Derivatives by an Iridium-Catalyzed C?H Activation with Silyldimesitylborane
Shishido, Ryosuke,Sasaki, Ikuo,Seki, Tomohiro,Ishiyama, Tatsuo,Ito, Hajime
, p. 12924 - 12928 (2019/11/05)
Direct dimesitylborylation of benzofuran derivatives by a C?H activation catalyzed by an iridium(I)/N-heterocyclic carbene (NHC) complex in the presence of Ph2MeSi-BMes2 afforded the corresponding dimesitylborylation products in good to high yield with excellent regioselectivity. This method provides a straightforward route to donor–(π-spacer)–acceptor systems with intriguing solvatochromic luminescence properties.
A vicarious, one-pot synthesis of benzo- and naphthofurans: Applications to the syntheses of stereumene B and paeoveitols
Rashid, Showkat,Bhat, Bilal A.,Mehta, Goverdhan
supporting information, p. 1122 - 1125 (2019/03/26)
An interesting albeit unexpected deviation during attempted Tanabe γ-lactone annulation on 4-hydroxycyclohexanones has led to a general, one-pot synthesis of benzofurans and naphtho[2,3–b]furans from readily assembled precursors. The utility of this adaptable methodology has been demonstrated through concise syntheses of natural products, stereumene B, paeoveitol D and (±)-paeoveitol.
Ni: Vs. Pd in Suzuki-Miyaura sp2-sp2 cross-coupling: A head-to-head study in a comparable precatalyst/ligand system
West, Matthew J.,Watson, Allan J. B.
supporting information, p. 5055 - 5059 (2019/06/03)
The Suzuki-Miyaura reaction is a cornerstone method for sp2-sp2 cross-coupling in industry. There has been a concerted effort to enable the use of Ni catalysis as an alternative to Pd in order to mitigate cost and improve sustainability. Despite significant advances, ligand development for Ni-catalyzed Suzuki-Miyaura cross-coupling remains underdeveloped when compared to Pd and, as a consequence, ligands for Ni-catalyzed processes are typically taken from the Pd arena. In this study we evaluate the effect of using a similar Ni and Pd precatalyst based on a common bidentate ligand (dppf) in a head-to-head format for the most common type of biaryl couplings, establishing the practical implications of direct replacement of Pd with Ni, and identifying the potential origins of these observations in a mechanistic context.
Copper-Catalyzed Ring Opening of Benzofurans and an Enantioselective Hydroamination Cascade
Xu-Xu, Qing-Feng,Liu, Qiang-Qiang,Zhang, Xiao,You, Shu-Li
, p. 15204 - 15208 (2018/10/24)
A copper(II) acetate/(R)-DTBM-SEGPHOS-catalyzed ring opening of benzofurans and enantioselective hydroamination cascade with dimethoxymethylsilane (DMMS) and hydroxylamine esters is described. Starting from readily available substituted benzofurans, a series of chiral N,N-dibenzylaminophenols, which are of high interest in pharmaceutical chemistry, were obtained with excellent enantioselectivities (up to 66 % yield, 94 % ee).
Palladium-Catalyzed Regioselective C-2 Arylation of Benzofurans with N′-Acyl Arylhydrazines
Cao, Jun,Chen, Zi-Li,Li, Shu-Min,Zhu, Gao-Feng,Yang, Yuan-Yong,Wang, Cong,Chen, Wen-Zhang,Wang, Jian-Ta,Zhang, Ji-Quan,Tang, Lei
supporting information, p. 2774 - 2779 (2018/06/21)
A novel ligand-free palladium-catalyzed C-2 arylation of benzofurans has been developed using N′-acyl arylhydrazines as the coupling partners and TEMPO as an oxidant. This protocol features a wide functional-group tolerance and highly regioselective products with good to excellent yields.
Spatially isolated palladium in porous organic polymers by direct knitting for versatile organic transformations
Wang, Xinbo,Min, Shixiong,Das, Swapan K.,Fan, Wei,Huang, Kuo-Wei,Lai, Zhiping
, p. 101 - 109 (2017/10/06)
We report here a direct knitting Method for preparation of highly robust, effective while air- and moisture-tolerant, and readily recyclable three-dimensional (3D) porous polymer-Pd network (PPPd) from the widely used Pd(PPh3)4. Electro-beam induced Pd atom crystallization was observed for the first time in organic polymer and revealed the ultrafine dispersion of palladium atoms. Challenging types of Suzuki-Miyaura couplings, reductive coupling of aryl halides and oxidative coupling of arylboronic acid were successively catalyzed by PPPd in aqueous media. Also catalytically selective C–H functionalization reactions were achieved with orders of magnitude more efficient than conventional Pd homogeneous catalysts. The strategy developed here provides a practical method for easy-to-make yet highly efficient heterogeneous catalysis.
Visible light-induced monofluoromethylenation of heteroarenes with ethyl bromofluoroacetate
Yu, Wei,Xu, Xiu-Hua,Qing, Feng-Ling
, p. 6564 - 6567 (2016/08/09)
Visible light-induced monofluoromethylenation of benzofurans and benzothiophenes with ethyl bromofluoroacetate was developed. This method provided a convenient access to novel α-fluoro-α-heteroarylesters under mild reaction conditions.
