69936-53-4Relevant academic research and scientific papers
Palladium-Catalyzed Synthesis of Tricyclic Indoles via a N-S Bond Cleavage Strategy
Zhang, Bo-Sheng,Wang, Fan,Gou, Xue-Ya,Yang, Ying-Hui,Jia, Wan-Yuan,Liang, Yong-Min,Wang, Xi-Cun,Li, Yuke,Quan, Zheng-Jun
supporting information, p. 7518 - 7523 (2021/10/01)
In palladium/norbornene (Pd/NBE) chemistry, the "ortho effect"has been proven to be a key factor in the process of β-carbon elimination to extrude NBE. Herein, we found that the o-iodoaniline protected by a p-methoxybenzenesulfonyl group can recover the "
Ruthenium-catalyzed cascade C-H activation/annulation of: N -alkoxybenzamides: Reaction development and mechanistic insight
Harvey, Jeremy N.,Song, Liangliang,Tang, Xiao,Van Der Eycken, Erik V.,Van Der Eycken, Johan,Van Meervelt, Luc,Zhang, Xiaoyong
, p. 11562 - 11569 (2020/11/23)
A highly selective ruthenium-catalyzed C-H activation/annulation of alkyne-tethered N-alkoxybenzamides has been developed. In this reaction, diverse products from inverse annulation can be obtained in moderate to good yields with high functional group compatibility. Insightful experimental and theoretical studies indicate that the reaction to the inverse annulation follows the Ru(ii)-Ru(iv)-Ru(ii) pathway involving N-O bond cleavage prior to alkyne insertion. This is highly different compared to the conventional mechanism of transition metal-catalyzed C-H activation/annulation with alkynes, involving alkyne insertion prior to N-O bond cleavage. Via this pathway, the in situ generated acetic acid from the N-H/C-H activation step facilitates the N-O bond cleavage to give the Ru-nitrene species. Besides the conventional mechanism forming the products via standard annulation, an alternative and novel Ru(ii)-Ru(iv)-Ru(ii) mechanism featuring N-O cleavage preceding alkyne insertion has been proposed, affording a new understanding of transition metal-catalyzed C-H activation/annulation.
Nickel-Catalyzed Formal Aminocarbonylation of Unactivated Alkyl Iodides with Isocyanides
Chen, Yifeng,Huang, Wenyi,Qu, Jingping,Shrestha, Mohini,Wang, Yun,Weng, Yangyang
supporting information, p. 3245 - 3250 (2020/04/21)
Herein, we disclose a Ni-catalyzed formal aminocarbonylation of primary and secondary unactivated aliphatic iodides with isocyanides to afford alkyl amide, which proceeds via the selective monomigratory insertion of isocyanides with alkyl iodides, subsequent β-hydride elimination, and hydrolysis process. The reaction features wide functional group tolerance under mild conditions. Additionally, the selective, one-pot hydrolysis of reaction mixture under acid conditions allows for expedient synthesis of the corresponding alkyl carboxylic acid.
Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O-H and N-H Additions
Costello, Jeff P.,Ferreira, Eric M.
, p. 9934 - 9939 (2019/12/24)
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization of the alkyne that leads to preferential heteroatom attack at the more electron-deficient carbon. The electronic effects are studied in other contexts, including hydroacyloxylation and hydroamination, and similar trends in directionality are predominant although not uniformly observed.
Gold-Catalyzed Hydrofluorination of Internal Alkynes Using Aqueous HF
Gauthier, Rapha?l,Mamone, Marius,Paquin, Jean-Fran?ois
supporting information, p. 9024 - 9027 (2019/11/14)
The gold-catalyzed hydrofluorination reaction of internal alkynes using hydrofluoric acid is reported. Notably, those conditions use one of the most economical sources of HF and are free of additional additives. Both symmetrical and unsymmetrical internal alkynes can be utilized, and the use of alkynes bearing a fluorinated group at the propargylic position as substrates allowed for a regioselective hydrofluorination reaction.
Ni-Catalyzed Cyclization of Enynes and Alkynylboronates: Atom-Economical Synthesis of Boryl-1,4-dienes
Cabrera-Lobera, Natalia,Quirós, M. Teresa,Bu?uel, Elena,Cárdenas, Diego J.
supporting information, p. 14512 - 14516 (2019/11/11)
We report a novel atom-economical Ni-catalyzed cyclization reaction of enynes with alkynylboronates. The reaction employs a non-expensive Ni salt, a phosphine-based ligand and easy-handling alkynylboronates as boron–carbon source. The reaction provides co
Synthesis of Primitive Dendrimer Systems Bearing Bicyclo[3,2,0]Hept-6-en-6-yl Groups via Unique Au-catalyzed [2+2] Cyclization
Lee, Kyu Hwan,Jillella, Raveendra,Kim, Jaewoong,Oh, Chang Ho
supporting information, p. 651 - 656 (2018/04/30)
Propargylic pivaloates bearing an alkynyl group at a three-carbon tether under the gold catalysis would undergo [3,3] rearrangements of propargylic pivaloates followed by tandem [2+2] cyclization to give the corresponding 6-acylbicyclo[3,2,0]hept-6-ens. In continuing work, we prepared various substrates bearing two arms of alkyne-propargylic pivaloates to explore primitive dendrimer concept bicyclic compounds. Finally, we could obtain a series of diasteromeric compounds bearing two arms of 6-acylbicyclo[3,2,0]hept-6-ene groups in high yields.
Titanium-Promoted Cross-Coupling for the Selective Synthesis of Polysubstituted, Conjugated Amides
Chenniappan, Vinoth Kumar,Rahaim, Ronald J.
supporting information, p. 5090 - 5093 (2016/10/14)
α,β-Unsaturated amides are important building blocks and are key structural elements in a number of biologically active natural products. Despite their importance and prevalence, few methods exist to prepare conjugated amides directly and modularly. To address this gap, a titanium-promoted coupling of alkynes and isocyanates has been developed. The method is highly stereoselective, producing only the E isomer with good chemoselectivity and regioselectivity (>95/5), for unsymmetrical internal alkynes that contain a steric bias. The reactive titanacyclopentene intermediate formed from the coupling of the alkyne and isocyanate was additionally reacted with various electrophiles to access tetrasubstituted enamides.
Ni-Catalyzed Carboxylation of Unactivated Alkyl Chlorides with CO2
B?rjesson, Marino,Moragas, Toni,Martin, Ruben
supporting information, p. 7504 - 7507 (2016/07/06)
A catalytic carboxylation of unactivated primary, secondary, and tertiary alkyl chlorides with CO2 at atmospheric pressure is described. This protocol represents the first intermolecular cross-electrophile coupling of unactivated alkyl chlorides, thus leading to new knowledge in the cross-coupling arena.
Ethylene transposition: Ruthenium hydride catalyzed intramolecular trans -silylvinylation of internal alkynes
Liu, Shasha,Zhao, Jinbo,Kaminsky, Lauren,Wilson, Robert J.,Marino, Nadia,Clark, Daniel A.
supporting information, p. 4456 - 4459 (2015/01/16)
A highly selective intramolecular trans-silylvinylation of internal alkynes catalyzed by RuHCl(CO)(SIMes)(PPh3) has been accomplished. The use of methyl vinyl ketone as an additive increased the efficiency of this transformation. This process w
