22927-00-0Relevant academic research and scientific papers
Addition reactions of organic carbanion equivalents via hydrazones in water
Wang, Yi-Zhan,Liu, Qi,Cheng, Liang,Yu, Song-Chen,Liu, Li,Li, Chao-Jun
, (2021/01/11)
The addition of organometallic reagents to unsaturated bonds is one of the most powerful tools for carbon–carbon bond formations. Alkylation through organometallic reagents requires stoichiometric quantity of metal and tedious anhydrous operation in most cases. Here, we report “umpolung” nucleophilic additions of hydrazones to Michael acceptors, carbonyls and imines in water. Under the catalysis of ruthenium(II), the addition reactions could be carried out in pure water to provide various alkylation products in moderate to good yields.
Influence of the methyl group at C=C bridging bond of stilbene on the longest wavelength maximum in ultraviolet absorption spectra
Zhang, Yanxiu,Cao, Chao-Tun,Zhang, Jingyuan,Cao, Chenzhong
supporting information, (2017/09/30)
The compounds stilbenes XArCH=CHArY(XSBY) and 1,2-diphenylpropylenes XArC(Me)=CHArY(XSMBY) have bridging groups CH=CH and C(CH3)=CH, respectively, in which the C(CH3)=CH has a side-group CH3 at the carbon-carbon double bond. A series of XSMBY were synthesized, and their longest wavelength maximum λmax (nm) in ultraviolet absorption spectra were measured in this work. We investigated the change regularity of the νmax (cm-1, νmax?=?1/λmax) of XSMBY and compared it with that of XSBY. The results indicate that (1) there is no good linear relationship between the νmax of XSMBY and that of XSBY. (2) Because of the influence of the side-group CH3, in case of the same couple of groups X and Y, the λmax of XSMBY is shorter than that of XSBY, that is, it has a blue shift. (3) The cross-interaction between the side-group CH3 and Y has an important effect on the νmax of XSMBY, while the cross-interaction between the side-group CH3 and X has a little effect on the νmax and can be ignored. (4) The specific cross-interaction between X and Y has important effect on the νmax of XSMBY, whereas it has no important effect on the νmax of XSBY.
Chloride-Bridged Dinuclear Rhodium(III) Complexes Bearing Chiral Diphosphine Ligands: Catalyst Precursors for Asymmetric Hydrogenation of Simple Olefins
Kita, Yusuke,Hida, Shoji,Higashihara, Kenya,Jena, Himanshu Sekhar,Higashida, Kosuke,Mashima, Kazushi
supporting information, p. 8299 - 8303 (2016/07/19)
Efficient rhodium(III) catalysts were developed for asymmetric hydrogenation of simple olefins. A new series of chloride-bridged dinuclear rhodium(III) complexes 1 were synthesized from the rhodium(I) precursor [RhCl(cod)]2, chiral diphosphine ligands, and hydrochloric acid. Complexes from the series acted as efficient catalysts for asymmetric hydrogenation of (E)-prop-1-ene-1,2-diyldibenzene and its derivatives without any directing groups, in sharp contrast to widely used rhodium(I) catalytic systems that require a directing group for high enantioselectivity. The catalytic system was applied to asymmetric hydrogenation of allylic alcohols, alkenylboranes, and unsaturated cyclic sulfones. Control experiments support the superiority of dinuclear rhodium(III) complexes 1 over typical rhodium(I) catalytic systems.
Catalyst-controlled highly selective coupling and oxygenation of olefins: A direct approach to alcohols, ketones, and diketones
Su, Yijin,Sun, Xiang,Wu, Guolin,Jiao, Ning
supporting information, p. 9808 - 9812 (2013/09/23)
Oxygen? That's radical! A method for the direct synthesis of substituted alcohols, ketones, and diketones through a catalyst-controlled highly chemoselective coupling and oxygenation of olefins has been developed. The method is simple and practical, can be switched by the selection of different catalysts, and employs molecular oxygen as both an oxidant and a reagent. Copyright
Iron-catalysed tandem cross-dehydrogenative coupling (CDC) of terminal allylic C(sp3) to C(sp2) of styrene and benzoannulation in the synthesis of polysubstituted naphthalenes
Liu, Hua,Cao, Li,Sun, Jia,Fossey, John S.,Deng, Wei-Ping
supporting information; scheme or table, p. 2674 - 2676 (2012/04/04)
A novel iron-catalysed tandem cross-dehydrogenative coupling and benzoannulation process was developed for the synthesis of biologically and synthetically important polysubstituted naphthalene derivatives from simple 1,2-aryl-propenes and styrenes in moderate to good yields. The Royal Society of Chemistry 2012.
Ultrasound-Mediated Synthesis and Mass Spectrometric Fragmentation of Dimethyl-Substituted 1,2-Diphenylethanols, Convenient Dimethylstilbene Precursors
Burkow, Ivan C.,Sydnes, Leiv K.,Ubeda, Danielle C. N.
, p. 235 - 244 (2007/10/02)
1,2-Diarylethanols were obtained in high yields by ultrasonic irradiation of mixtures of lithium sand, benzylic chlorides, and arenecarbaldehydes or aryl methyl ketones.The mass spectra of the alcohols contained dominant peaks for species formed by dehydration, α-cleavage processes and rearrangement involving hydrogen transfer.Acid-catalyzed dehydration of the alcohols gave the corresponding stilbenes in quantitative yields.
MECHANISM OF INTRAMOLECULAR CYCLIZATION IN ARYL 2-CYCLOPROPYLPHENYL SULFONES UNDER CONDITIONS OF ACID ISOMERATION
Pisanova, E. V.,Saginova, L. G.,Shabarov, Yu. S.
, p. 278 - 281 (2007/10/02)
Treatment of phenyl and p-tolyl 2-cyclopropylphenyl sulfones with concentrated sulfuric acid at 20 deg C leads to intramolecular cyclization with the formation of 10-methyl-10,11-dihydrobenzothiepin 5,5-dioxide and 8,10-dimethyl-10,11-dihydrobenzothiepin 5,5-dioxide.The reaction involves attack by the carbocation which forms at the ortho position of the adjacent benzene ring.
