- Predicting and optimizing asymmetric catalyst performance using the principles of experimental design and steric parameters
-
Using a modular amino acid based chiral ligand motif, a library of ligands was synthesized systematically varying the substituents at two positions. The effects of these changes on ligand structure were probed in the enantioselective allylation of benzald
- Harper, Kaid C.,Sigman, Matthew S.
-
-
Read Online
- A Green approach for allylations of aldehydes and ketones: Combining allylborate, mechanochemistry and lanthanide catalyst
-
Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.
- De Souza, Viviane P.,Oliveira, Cristiane K.,De Souza, Thiago M.,Menezes, Paulo H.,Alves, Severino,Longo, Ricardo L.,Malvestiti, Ivani
-
-
- Hydroalumination of terminal β-acetylene alcohols with lithium aluminum hydride
-
Hydrogenation of terminal β-acetylene alcohols with lithium aluminum hydride in THF has afforded homoallylic alcohols. Decomposition of the intermediate organoaluminum complex with deuterated water, iodine, or pyridinium dibromide has evidenced about the non-regioselective hydride attack at the triple bond.
- Garibyan,Makaryan,Ogannisyan,Chobanyan
-
p. 267 - 272
(2016/04/20)
-
- Tin mediated Barbier type allylation in ionic liquids
-
The Barbier type allylation of carbonyl compounds is a useful organic transformation as the resultant homoallylic alcohols are important building blocks for many biologically active molecules. Tin mediated Barbier allylation of different carbonyl compounds in room temperature ionic liquid, [BMIM][BF 4] afforded the corresponding homoallylic alcohols in good to excellent yields. The ionic liquid was successfully recycled and reused in allylation reactions.
- Slaton, Rahiem,Petrone, Adam,Manchanayakage, Renuka
-
experimental part
p. 5073 - 5076
(2011/10/09)
-
- Allylation of carbonyl compounds mediated by Aluminum/Fluoride salts in water
-
A novel mediator (Al/KF) has been developed and employed in the Barbier-type alkylations of various aldehydes and ketones with alkyl halide in water. The carbonyl compounds could be effectively converted into corresponding homoallylic alcohol in good yiel
- Yuan, Shizhen,Liu, Jin,Xu, Ling,Zhu, Shaofeng
-
experimental part
p. 578 - 582
(2010/10/04)
-
- Synthesis of homoallylic alcohols from ketones in water
-
Homoallylic alcohols have been prepared in good yields by allylation of ketones with allyl bromide in the presence of stannous chloride dihydrate, zinc iodide, and ammonium chloride in water. Copyright Taylor & Francis LLC.
- Wang, Jun,Yuan, Gu
-
p. 401 - 405
(2007/10/03)
-
- Barbier-type reaction mediated with tin nano-particles in water
-
Tin nano-particles are employed in the Barbier-type allylation reaction of carbonyl compounds in water to afford the corresponding homoallylic alcohols in good yields. The in situ generated allylation intermediates, allyltin(II) bromide and diallyltin dib
- Zha, Zhenggen,Qiao, Shu,Jiang, Jiaoyang,Wang, Yusong,Miao, Qian,Wang, Zhiyong
-
p. 2521 - 2527
(2007/10/03)
-
- SnCl2-mediated carbonyl allylation in fully aqueous media
-
Systematic studies were performed on SnCl2-mediated carbonyl allylation reaction between aldehydes and allyl halides in fully aqueous media. Totally three valuable reaction systems were discovered, which were SnCl 2/CuCl2, SnCl2/TiCl3, and SnCl 2/PdCl2. They all provided good to excellent yields in the allylation of aliphatic and aromatic aldehydes under very mild and convenient conditions. SnCl2, by itself, was also found to be effective for the allylation reaction when allyl bromide was employed. However, the SnCl 2-only reaction could only tolerate very small amount of water as the solvent. The SnCl2/CuCl2, SnCl2/TiCl 3, and SnCl2/PdCl2-mediated reactions exhibited good regioselectivity favoring the γ-adduct when cinnamyl halides were employed as the allylation reagent. The same reactions with cinnamyl halides also showed good diastereoselectivity favoring the anti-product. Mechanistic studies using proton NMR techniques suggested that the additive (i.e., CuCl 2, TiCl3, PdCl2) could accelerate the formation of allyltin intermediate, but this step was shown not to be the most important for the allylation. Thus we proposed that the Lewis acid catalysis effect exerted by the additive was the main reason for the observed reactivity enhancement.
- Tan, Xiang-Hui,Hou, Yong-Quan,Huang, Chao,Liu, Lei,Guo, Qing-Xiang
-
p. 6129 - 6136
(2007/10/03)
-
- Organometallic reactions in aqueous media: The allylations of carbonyl compounds mediated in Zn/CdSO4 and Zn/SnCl2 bimetal systems
-
Zn/CdSO4 and Zn/SnCl2 bimetal systems were employed in the allylations of aldehydes or ketones in distilled water to afford the corresponding homoallylic alcohols in good yields. Also, the chemoselectivity was studied under the same
- Zhou, Cunliu,Zhou, Yuqing,Jiang, Jiaoyang,Xie, Zhen,Wang, Zhiyong,Zhang, Jiahai,Wu, Jihui,Yin, Hao
-
p. 5537 - 5540
(2007/10/03)
-
- Novel ultrasonication-assisted carbonyl allylation mediated by SnCl 2 in water
-
Under ultrasonication, it was found that SnCl2 could efficiently mediate the aqueous Barbier reactions between carbonyl compounds and allyl bromide to give the corresponding homoallylic alcohols in high yields without using any Lewis acid catalyst.
- Wang, Jun,Yuan, Gu,Dong, Chang-Qing
-
p. 286 - 287
(2007/10/03)
-
- Allylation of carbonyl compounds mediated by nanometer-sized bismuth in water
-
It is found that nanometer-sized bismuth mediates the allylation of carbonyl compounds in water to afford the corresponding homoallylic alcohol in high yields. Nanometer-sized bismuth is much more effective than regular bismuth powder in this reaction.
- Xu, Xiaolan,Zha, Zhenggen,Miao, Qian,Wang, Zhiyong
-
p. 1171 - 1174
(2007/10/03)
-
- High regio- and stereoselective Barbier reaction of carbonyl compounds mediated by NaBF4/Zn (Sn) in water
-
Studies with NaBF4/M (M = Zn or Sn) showed that this novel mediator facilitated allylation of a variety of carbonyl compounds in water and had a great influence on the diastereoselectivity of the addition. More importantly, α- and γ-addition pr
- Zha, Zhenggen,Xie, Zhen,Zhou, Cunliu,Chang, Mingxin,Wang, Zhiyong
-
p. 1297 - 1300
(2007/10/03)
-
- Novel carbonyl allylation mediated by SnCl2/Cu in water
-
Copper metal was found to be able to catalyze SnCl2-mediated coupling between carbonyl compounds and allyl halides to give the corresponding homoallylic alcohols in high yields.
- Tan, Xiang-Hui,Shen, Bo,Liu, Lei,Guo, Qing-Xiang
-
p. 9373 - 9376
(2007/10/03)
-
- Gallium-mediated allylation of carbonyl compounds in water
-
Ga-mediated allylation of aldehydes or ketones in distilled or tap water generated the corresponding homoallyl alcohols in high yields without the assistance of either acidic media or sonication.
- Wang, Zhiyong,Yuan, Shizhen,Li, Chao-Jun
-
p. 5097 - 5099
(2007/10/03)
-
- Application of tin and nanometer tin in allylation of carbonyl compounds in tap water.
-
[reaction: see text] Nanometer tin-mediated allylation of aldehydes or ketones in distilled or tap water gave rise to corresponding homoallyl alcohol in high yield without any other assistance such as heat or supersonic or acidic media.
- Wang, Zhiyong,Zha, Zhenggen,Zhou, Cunliu
-
p. 1683 - 1685
(2007/10/03)
-
- Organometallic Reactions in Aqueous Media. the Nature of the Organotin Intermediate in the Tin-Mediated Allylation of Carbonyl Compounds
-
Allyl bromide and tin reacted in aqueous media to give first allyltin(II) bromide (5) and then diallyltin dibromide (4). Either organotin intermediate can react with carbonyl compounds to give the corresponding homoallylic alcohols. Competitive experiment
- Chan, Tak Hang,Yang, Yang,Li, Chao Jun
-
p. 4452 - 4455
(2007/10/03)
-
- Solvent-Mediated Allylation of Carbonyl Compounds with Allylic Stannanes
-
Methanol promotes the addition of allyltrimethylstannane (1a) to isobutyraldehyde (2a, 30 °C) yielding the corresponding homoallylic alcohol (3a), without the necessity for added catalyst. The corresponding reaction of aldehydes 2a-e or activated ketone 2
- Cokley, Teresa M.,Harvey, Peta J.,Marshall, Raymond L.,McCluskey, Adam,Young, David J.
-
p. 1961 - 1964
(2007/10/03)
-
- Allylboration of some ketones and aldehydes with 2-allyl-1,2-oxaborolane. Isolation of their intermediate adducts and synthesis of homoallylic alcohols
-
2-Allyl-1,2-oxaborolane (II), prepared by the reaction of 2-allyloxy-1,2-oxaborolane (I) with allylmagnesium bromide in ether, is an extremely reactive allylborane.This cyclic borinate ester II is a BCCO-type organoborane and can be used as a novel allylborating reagent.As is usual with allylboranes, II can also add smoothly to various ketones or aldehydes, and when followed by deboronation with diethanolamine gives the corresponding homoallylic alcohols IV.The adducts III, formed via a six-centre cyclic mechanism and allylic rearrangement, have been isolated and identified as a kind of 2-alkenoxy-1,2-oxaborolane.
- Zhou, Weike,Liang, Shaofang,Yu, Su,Luo, Weiming
-
-
- C-CENTRED OPTICALLY ACTIVE ORGANOSILANES,2. APPLICATION TO ENANTIOSELECTIVE ALLYLATION OF CARBONYL COMPOUNDS.
-
C-Centred optically active allylsilanes react with carbonyl compounds in presence of Lewis acids to give the corresponding homoallyl alcohols with ee varying from 21 to 56percent.The role of the Lewis acid is crucial for a correct development of the reaction; different procedures are tested and the results compared.
- Coppi, Laura,Mordini, Alessandro,Taddei, Maurizio
-
p. 969 - 972
(2007/10/02)
-
- COPPER(I)-CATALYZED REACTION OF ISOPRENE BROMOHYDRIN WITH ORGANOLITHIUM REAGENT
-
The reaction of isoprene bromohydrin (1-bromo-2-methyl-3-buten-2-ol) (1) with ethyl-, propyl- and butyllithium in the presence of copper(I) iodide leads to the exclusive formation of the vinyl group migrated 2-alkyl-4-penten-2-ols (3d-3f), in contrast to
- Araki, Shuki,Butsugan, Yasuo
-
p. 185 - 186
(2007/10/02)
-