92804-32-5Relevant academic research and scientific papers
Heterogeneous Rh and Rh/Ag bimetallic nanoparticle catalysts immobilized on chiral polymers
Min, Hyemin,Miyamura, Hiroyuki,Yasukawa, Tomohiro,Kobayashi, Shu
, p. 7619 - 7626 (2019/08/20)
The development of heterogeneous chiral catalysts has lagged far behind that of homogeneous chiral catalysts in spite of their advantages, such as environmental friendliness for a sustainable society. We describe herein novel heterogeneous chiral Rh and Rh/Ag bimetallic nanoparticle catalysts consisting of polystyrene-based polymers with chiral diene moieties. The catalysts enable high-to-excellent yields and enantioselectivities to be obtained in asymmetric 1,4-addition reactions of arylboronic acids with α,β-unsaturated carbonyl compounds such as ketones, esters, and amides, and in other asymmetric reactions. The catalysts could be readily recovered by simple filtration and reused; they could also be applied to continuous-flow synthesis. We also discuss the nature of possible reaction species based on XPS analysis.
CuH-Catalyzed Asymmetric Reduction of α,β-Unsaturated Carboxylic Acids to β-Chiral Aldehydes
Zhou, Yujing,Bandar, Jeffrey S.,Liu, Richard Y.,Buchwald, Stephen L.
supporting information, p. 606 - 609 (2018/01/26)
The copper hydride (CuH)-catalyzed enantioselective reduction of α,β-unsaturated carboxylic acids to saturated aldehydes is reported. This protocol provides a new method to access a variety of β-chiral aldehydes in good yields, with high levels of enantioselectivity and broad functional group tolerance. A reaction pathway involving a ketene intermediate is proposed based on preliminary mechanistic studies and density functional theory calculations.
Triazolium salts as appropriate catalytic scaffolds for 1,4-additions to α,β-unsaturated carbonyls
Bratko, Ielyzaveta,Guisado-Barrios, Gregorio,Favier, Isabelle,Mallet-Ladeira, Sonia,Teuma, Emmanuelle,Peris, Eduardo,Gomez, Montserrat
, p. 2160 - 2167 (2014/04/17)
1,2,3-Triazole derivatives containing a rigid dihydroanthracenyl skeleton are suitable precursors for both organometallic and organo-based catalysts. A Rh-carbene complex and the triazolium salt efficiently catalyzed the 1,4-additions of C- and heterodonor reagents to α,β-unsaturated carbonyl substrates, respectively. Copyright
Pd-arylurea complexes for the Heck arylation of crotonic and cinnamic substrates
Smith, Matthew R.,Kim, Jung Yun,Ciufolini, Marco A.
, p. 2042 - 2045 (2013/04/24)
A catalyst consisting of the 1:2 complex of Pd(OAc)2 (1 mol %) with N-(4-carbethoxy)-phenylurea promotes the Heck arylation of a range of crotonic and cinnamic substrates, including aldehydes, ketones, esters, and nitriles, with electron-rich - but not electron-deficient - aryl iodides.
Chiral dihydrobenzo[1,4]oxazines as catalysts for the asymmetric transfer-hydrogenation of α,β-unsaturated aldehydes
Ebner, Christian,Pfaltz, Andreas
, p. 10287 - 10290 (2012/02/01)
A new class of organocatalysts based on the structure of 2,3-dihydrobenzo[1,4]oxazine was prepared and applied in the enantioselective transfer-hydrogenation of α,β-unsaturated aldehydes with Hantzsch ester as hydride donor. These catalysts proved to be particularly effective for the conjugate reduction of β,β-diaryl-substituted acrylaldehydes leading to saturated aldehydes bearing a stereogenic center with two different aryl groups with enantioselectivities of up to 91% ee.
PH-Dependent conjugate addition of arylboronic acids to α,β-unsaturated enones catalyzed by a reusable palladium(II)/cationic 2,2'-bipyridyl system in water under air
Huang, Shao-Hsien,Wu, Tzu-Min,Tsai, Fu-Yu
experimental part, p. 619 - 624 (2010/11/04)
A reusable Pd(NH3)2Cl2/cationic 2,2'-bipyridyl system for the catalysis of the conjugate addition of arylboronic acids to α,β-unsaturated enones in water under air was developed. Addition of arylboronic acids to both cyclic and acyclic enones progressed smoothly, providing the products in good to high yields, the best result being obtained when HBF4 was used to adjust the pH value to 1.0. After the reaction, the residual aqueous solution could be reused several times,making the reaction greener and reducing wastage of precious metals. Copyright
Regio- and stereoselective heck α-arylation of cinnamyl alcohols
Ambrogio, Ilaria,Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Sgalla, Simona
scheme or table, p. 620 - 624 (2009/07/11)
The Heck reaction of cinnamyl alcohols with aryl iodides has been investigated using n-Bu4NOAc as the base in toluene. Under these conditions, the reaction affords regio- and stereoselectively (Z)-2,3-diarylallylic alcohols in moderate to good yields. Experimental evidence suggests that the observed selectivity in formation of the vinylic substitution products is kinetic in origin under these conditions and that both the base and the solvent play a key role. Georg Thieme Verlag Stuttgart.
Palladium-catalyzed Heck arylations of allyl alcohols in ionic liquids: Remarkable base effect on the selectivity
Calo, Vincenzo,Nacci, Angelo,Monopoli, Antonio,Ferola, Valentina
, p. 2596 - 2601 (2007/10/03)
Pd-catalyzed Heck arylation of allyl alcohols in tetraalkylammonium ionic liquids (ILs) can be made highly selective toward the formation of either aromatic carbonyl compounds or aromatic conjugated alcohols by carefully choosing both the IL and the base.
Enantioselective preparation of 1,1-diarylethanes: Aldehydes as removable steering groups for asymmetric synthesis
Fessard, Thomas C.,Andrews, Stephen P.,Motoyoshi, Hajime,Carreira, Erick M.
, p. 9331 - 9334 (2008/12/21)
Cut it out! Convenient procedures have been delineated for the synthesis of optically active, functionalized 1,1-diaryl-ethanes by decarbonylation of β,β-diaryl-propionaldehydes. The process can be conducted as a one-pot 1,4-addition/decarbonylation sequence. Aldehydes are used as removable steering groups in this new strategy for the preparation of optically active building blocks. (Chemical Equation Presented)
Palladium(II)-catalyzed 1,4-addition of arylboronic acids to β-arylenals for enantioselective syntheses of 3,3-diarylalkanals: a short synthesis of (+)-(R)-CDP 840
Nishikata, Takashi,Yamamoto, Yasunori,Miyaura, Norio
, p. 4007 - 4010 (2008/02/04)
1,4-Addition of arylboronic acid to trans-β-arylenals proceeded smoothly in acetone-water (10/1) at 10-25 °C in the presence of [Pd(S,S-chiraphos)(PhCN)2](SbF6)2 (0.5 mol %), AgX (X = BF4, SbF6, 10 mo
