70964-90-8Relevant articles and documents
Iron-catalyzed stereospecific arylation of enol tosylates using Grignard reagents
Wei, Yi-Ming,Ma, Xiao-Di,Wang, Lei,Duan, Xin-Fang
supporting information, p. 1101 - 1104 (2020/02/04)
The stereospecific Fe-catalyzed arylation of enol tosylates was reported. Various tri- or tetrasubstituted Z or E-enol tosylates of β-keto esters were arylated using common and Knochel-type Grignard reagents with complete stereofidelity. The precursors fo
Copper-Catalyzed 1,2-Methoxy Methoxycarbonylation of Alkenes with Methyl Formate
Budai, Balázs,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
, p. 10305 - 10309 (2019/06/27)
Reported here is a copper-catalyzed 1,2-methoxy methoxycarbonylation of alkenes by an unprecedented use of methyl formate as a source of both the methoxy and the methoxycarbonyl groups. This reaction transforms styrene and its derivatives into value-added β-methoxy alkanoates and cinnamates, as well as medicinally important five-membered heterocycles, such as functionalized tetrahydrofurans, γ-lactones, and pyrrolidines. A ternary β-diketiminato-CuI-styrene complex, fully characterized by NMR spectroscopy and X-ray crystallographic analysis, is capable of catalyzing the same transformation. These findings suggest that pre-coordination of electron-rich alkenes to copper might play an important role in accelerating the addition of nucleophilic radicals to electron-rich alkenes, and could have general implications in the design of novel radical-based transformations.
DMAP-Catalyzed [4 + 2] Cycloaddition of α,β-Unsaturated Carboxylic Acids with Ketones for Synthesis of α,β-Unsaturated δ-Lactones
Jin, Jinghai,Xu, Qinchang,Deng, Weiping
supporting information, p. 397 - 400 (2017/04/27)
The DMAP-catalyzed [4 + 2] cycloaddition of α,β-unsaturated carboxylic acids with ketones furnishing α,β-unsaturated δ-lactones in good yields (up to 80%) is described, which is the first example of remote γ-C(sp3)-H activation of α,β-unsaturated carboxylic acids facilitated by DMAP, a pyridine-based catalyst. Copyright
Highly efficient synthesis of chiral aromatic ketones: Via Rh-catalyzed asymmetric hydrogenation of β,β-disubstituted enones
Zhang, Tao,Jiang, Jun,Yao, Lin,Geng, Huiling,Zhang, Xumu
supporting information, p. 9258 - 9261 (2017/08/22)
A succinct and efficient protocol was developed for the synthesis of chiral aromatic ketones via asymmetric hydrogenation of β,β-disubstituted enones with rhodium catalysts based on chiral bisphosphine thiourea ligands. A series of substrates (17 examples) was smoothly catalyzed to afford the corresponding chiral aromatic ketones in high conversions (>99%) with excellent enantioselectivities (up to 96% ee).
Rhodium-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated Carbonyl Compounds via Thiourea Hydrogen Bonding
Wen, Jialin,Jiang, Jun,Zhang, Xumu
supporting information, p. 4451 - 4453 (2016/09/28)
The strategy of secondary interaction enables enantioselectivity for homogeneous hydrogenation. By introducing hydrogen bonding of substrates with thiourea from the ligand, α,β-unsaturated carbonyl compounds, such as amides and esters, are hydrogenated wi
Highly porous chitosan microspheres supported palladium catalyst for coupling reactions in organic and aqueous solutions
Zeng, Minfeng,Zhang, Xin,Shao, Linjun,Qi, Chenze,Zhang, Xian-Man
experimental part, p. 29 - 37 (2012/04/04)
Porous chitosan microspheres (PCMS) were prepared from crosslinking chitosan/polyethylene glycol (PEG) interpenetrating microspheres through selective dissolution of the water-soluble PEG component for the immobilization of palladium catalyst. The resultant Pd/PCMS supported palladium has been demonstrated as a highly active and easily recyclable heterogeneous catalyst for the Ullmann-type reductive homocoupling of aromatic halides and the Heck cross-coupling of aromatic halides with acrylates. Most interestingly, the prepared Pd/PCMS heterogeneous palladium catalyst can also be employed in the environmentally-benign aqueous solution due to the highly hydrophilic hydroxyl and amino functional groups of chitosan. The large size of the microsphere structure can greatly facilitate separation and recycling of the expensive and toxic palladium catalysts from the reaction mixture and the recovered Pd/PCMS catalyst can preserve the catalytic activity and selectivity for the Heck reaction without any observable degradation over ten recycling times. The high activity and stability of the Pd/PCMS catalyst have been attributed to a combination of the high specific surface area of the porous structure as well as the strong chelation of palladium species with the abundant chitosan surface hydroxyl, amino and carbonyl functional groups.
General, robust, and stereocomplementary preparation of β-ketoester enol tosylates as cross-coupling partners utilizing TsCl-N-methylimidazole agents
Nakatsuji, Hidefumi,Ueno, Kanako,Misaki, Tomonori,Tanabe, Yoo
supporting information; scheme or table, p. 2131 - 2134 (2009/05/26)
(Chemical Equation Presented) We have developed a general, robust, and cost-effective method for the (E)- or (Z)-stereocomplementary enol tosylation of β-ketoesters using TsCl-N-methylimidazole (NMI)-Et3N or LiOH. TsCl coupled with NMI formed a
Comparative study of Heck reaction under thermal and microwave conditions
Solabannavar,Desai, Uday V.,Mane
, p. 2235 - 2237 (2007/10/03)
Comparative study of Heck reaction of various substrates under thermal and microwave irradiation reveals advantage of microwave synthesis.
1-(2-Iodophenyl)-1H-tetrazole as a ligand for Pd(II) catalyzed Heck reaction
Gupta, Arun Kumar,Song, Chung Hyun,Oh, Chang Ho
, p. 4113 - 4116 (2007/10/03)
1-(2-Iodophenyl)-1H-tetrazole 2 was synthesized by the reaction of 2-iodoaniline, sodium azide and triethyl orthoformate in acetic acid. The newly synthesized ligand 2 was successfully used in Heck reaction to give the cross-coupled products in excellent yields.
[Bis(oxazolinyl)pyrrole]palladium complexes as catalysts in heck- and suzuki-type C-C coupling reactions
Mazet, Clement,Gade, Lutz H.
, p. 1161 - 1168 (2007/10/03)
The two bis(oxazoline)pyrrole ligand precursors 2,5-bis(4,4′-dimethyl-4,5-dihydrooxazol-2-yl)pyrrole ("dmoxpH", 2) and 2,5-bis(4,4′-dimethyl-4,5-dihydrooxazol-2-yl)-3,4-diethyl- pyrrole ("Et2dmoxpH", 5) have been synthesised and metallated by treatment with n-butyllithium at -78°C in diethyl ether. Treatment of the lithium pyrrolide with 1.1 molequiv. of [PdCl2(COD)] gave the corresponding helical dinuclear palladium complexes [Pd2Cl2(dmoxp)2] (6) and [Pd2Cl2(Et2dmoxp)2] (7). In both complexes the tridentate bis(oxazolinyl)pyrrolide ligands bridge the two metal centres, with one of the oxazoline rings and the charged pyrrolide being coordinated to the one Pd centre while the second oxazoline ring is twisted relative to the pyrrolide unit and coordinates to the second palladium atom. Complexes 6 and 7 were found to be precursors for active catalysts for Heck coupling reactions of styrene and ethyl acrylate, with turnover numbers of over 9000 for the former, as well as for disubstituted alkenes such as methyl crotonate and methyl cinnamate. Complex 6 was found to be a very active catalyst for Suzuki coupling reactions of activated and deactivated bromoarenes. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
