59767-24-7Relevant articles and documents
Isopropanol as a hydrogen source for single atom cobalt-catalyzed Wacker-type oxidation
An, Yue,Chen, Bo,Gao, Shuang,Huang, Guanwang,Luo, Huihui,Shang, Sensen,Wang, Lianyue
, p. 2769 - 2773 (2020/06/17)
The first example of a heterogeneous cobalt catalytic system for Wacker-type oxidation catalyzed by a single atom dispersed Co-N/C catalyst using alcohol as the hydrogen source under an oxygen atmosphere is presented. By combining a well-designed, controlled experiment and various methods of characterization, we determined that single atom cobalt was the active center rather than nanoparticle or oxide counterparts.
Bromomethyl Silicate: A Robust Methylene Transfer Reagent for Radical-Polar Crossover Cyclopropanation of Alkenes
Luo, Wenping,Fang, Yewen,Zhang, Li,Xu, Tianhang,Liu, Yongjun,Li, Yan,Jin, Xiaoping,Bao, Jiakan,Wu, Xiaodong,Zhang, Zongyong
supporting information, p. 1778 - 1781 (2020/03/11)
A general protocol for visible-light-induced cyclopropanation of alkenes was developed with bromomethyl silicate as a methylene transfer reagent, offering a robust tool for accessing highly valuable cyclopropanes. In addition to α-aryl or methyl-substituted Michael acceptors and styrene derivatives, the unactivated 1,1-dialkyl ethylenes were also shown to be viable substrates. Apart from realizing the cyclopropanation of terminal alkenes, the methyl transfer reaction has been further demonstrated to be amenable to the internal olefins. The photocatalytic cyclopropanation of 1,3-bis(1-arylethenyl)benzenes was also achieved, giving polycyclopropane derivatives in excellent yields. With late-stage cyclopropanation as the key strategy, the synthetic utility of this transformation was also demonstrated by the total synthesis of LG100268.
Scandium(III) Trifluoromethanesulfonate Catalyzed Selective Reactions of Donor–Acceptor Cyclopropanes with 1,1-Diphenylethanols: An Approach to Polysubstituted Olefins
Zhu, Xiaoyan,Hong, Gang,Hu, Chen,Wu, Shengying,Wang, Limin
supporting information, p. 1547 - 1551 (2017/04/01)
An unexpected synthetic approach to polysubstituted olefins through the scandium(III) trifluoromethanesulfonate catalyzed ring-opening reaction of donor–acceptor cyclopropanes with 1,1-diphenylethanols was developed. The reactions, which are experimentally easy to handle, feature tolerance of various functional groups and mild reaction conditions. On the basis of experimental evidence, a plausible mechanism was also proposed.
Al(OTf)3: An efficient lewis acid additive for domino addition-elimination of Grignard reagents to activated ketones
Pieterse, Tanya,Visser, Melanie,Marais, Charlene,Bezuidenhoudt, Barend C. B.
supporting information, p. 1541 - 1546 (2016/06/14)
It has been demonstrated that aluminium triflate in either stoichiometric or catalytic quantities facilitates the addition-elimination of Grignard reagents to electron-rich ketones, such as methoxy substituted acetophenones, propiophenone and chromanone in a one-pot process, and that it has an enhancing effect on the addition of these reagents to the ketones. It has also been found that the reactions are highly stereoselective towards one regioisomer of the alkene in the case of oxygenated aryl-alkyl substituted substrates, but not when the elimination originates from a double benzylic alcohol intermediate.
Catalytic Enantioselective Addition of Aryl Grignard Reagents to Ketones
Fernández-Mateos, Emilio,Maciá, Beatriz,Yus, Miguel
, p. 6519 - 6526 (2016/02/18)
We report a catalytic system for the challenging enantioselective addition of aryl Grignard reagents to ketones. Using a simple, one-pot procedure under mild conditions, a wide range of aromatic ketones are converted into diaryl alcohols in good yields and with good enantioselectivities. The catalytic enantioselective addition of aryl Grignard reagents to ketones is now possible. Using a readily available Ar-BINMOL ligand and titanium(IV) isopropoxide in a simple, one-pot procedure under mild conditions, a wide range of aromatic ketones are converted into diaryl alcohols in good yields and with good enantioselectivities.
Rhodium(I)-n-heterocyclic carbene-catalyzed addition of sodium tetraphenylborate to ketones to form tertiary alcohols
Yiit, Beyhan,Yiit, Murat,?zdemir, Ismail
, p. 2562 - 2571 (2015/01/09)
Rhodium complexes ([Rh(COD)(NHC)Cl]) were synthesized by the reaction of bis(1,3-dialkylperhydrobenzimidazolin-2-ylidene) with [RhClCOD]2 in toluene and characterized by elemental analysis, 1H NMR, 13C NMR and IR spectroscopy. These complexes were used as catalysts for the addition of sodium tetraphenylborate to aromatic ketones and corresponding tertiary alcohols were obtained in good yields.
Reaction of Grignard reagents with carbonyl compounds under continuous flow conditions
Riva,Gagliardi,Martinelli,Passarella,Vigo,Rencurosi
experimental part, p. 3242 - 3247 (2010/05/19)
This contribution details how a continuous flow reactor was used to react carbonyl compounds with Grignard reagents at room temperature in an efficient and safe manner. Flow rate, residence time and temperature were optimized for the preparation of a small collection of secondary and tertiary alcohols. Excellent yields and general applicability were observed using the set-up protocol. The procedure was also applied for the preparation of Tramadol, an analgesic drug belonging to the opioid group. The developed conditions allowed the selective addition of Grignard reagents to aldehydes and ketones in the presence of a nitrile function.
SUBSTITUTED BENZHYDRYLETHERS
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Page/Page column 35, (2009/08/18)
Disclosed herein are substituted benzhydrylethers of Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and methods of their use thereof.
Highly enantioselective arylation of aldehydes and ketones using AlArEt2(THF) as aryl sources
Zhou, Shuangliu,Wu, Kuo-Hui,Chen, Chien-An,Gau, Han-Mou
supporting information; experimental part, p. 3500 - 3505 (2009/09/30)
A series of AlArEt2(THF) (Ar = Ph (la), 4-MeC6H 4 (1b), 4-MeOC6H 4 (1c), 4-Me 3SiC6H4 (1d), 2-naphthyl (le)) were synthesized from reactions of AlEt2Br(THF) with ArMgBr. In CDC13 solution, the 1H NMR spectra showed that AlArEt2(THF) compounds exist as a mixture of four species of formulas of AlAr xEt3-x (THF) (x = 0, 1, 2, or 3). AlArEt2(THF) compounds were found to be superior and atom-economic reagents for asymmetric aryl additions to organic carbonyls. Aryl additions of AlArEt2(THF) to aldehydes catalyzed by the titanium(IV) complex of (R)-H8-BINOL were efficient with a short reaction time of 1 h, affording aryl addition products as exclusive or main products in high yields and excellent enantioselectivities of up to 98% ee. Although ethyl additions to aldehydes occurred in minor extent, this study demonstrates that increasing the amount of AlArEt2(THF) from 1.2 to 1.4 or to 1.6 equiv significantly improved the aryl addition products of up to >99%. On the other hand, asymmetric arylations of AlArEt2(THF) to ketones employing a titanium(IV) catalyst of (S)-BINOL produced optically active tertiary alcohols exclusively in excellent enantioselectivities of up to 94% ee.
