106035-79-4Relevant academic research and scientific papers
Enantioselective Copper-Catalyzed Methylboration of Alkenes
Chen, Bin,Cao, Peng,Liao, Yang,Wang, Min,Liao, Jian
, p. 1346 - 1349 (2018)
An enantioselective Cu-catalyzed borylative cross-coupling reaction of alkenes, bis(pinacolato)diboron (B2(pin)2), and methyl iodide is reported. Alkenes including styrenes, β-substituted styrenes, and challenging aliphatic olefins were smoothly transferred to the desired methylboration products with excellent diastereoselectivities (dr up to >99:1) and enantioselectivities (er up to 99:1). The utility of this process was demonstrated by the synthesis of naproxen and formal synthesis of two natural products.
Concise asymmetric total syntheses of (?)-nuciferol, (?)-nuciferal, and (?)-dihydrocurcumene via Rh(I)-catalyzed boronic acid addition
Pal, Souvik,Khatua, Arindam,Das, Mrinal K.,Bisai, Vishnumaya
supporting information, (2021/01/25)
A general catalytic asymmetric total synthesis of aromatic bisabolane sesquiterpenes, (?)-nuciferol (ent-1c), (?)-nuciferal (ent-1d), and (?)-dihydrocurcumene (ent-1h) have been achieved in 5–6 steps in high chemical yields from commercially available (E)
Iridium-catalyzed asymmetric hydrogenation of 3,3-disubstituted allylic alcohols in ethereal solvents
Bernasconi, Maurizio,Ramella, Vincenzo,Tosatti, Paolo,Pfaltz, Andreas
, p. 2440 - 2444 (2014/03/21)
Ir-phosphinomethyl-oxazoline complexes have been identified as efficient, highly enantioselective catalysts for the asymmetric hydrogenation of 3,3-disubstituted allylic alcohols and related homoallylic alcohols. In contrast to other N,P ligand complexes, which require weakly coordinating solvents, such as dichloromethane, these catalysts perform well in more ecofriendly THF or 2-MeTHF. Their synthetic potential was demonstrated with the formal total synthesis of four bisabolane sesquiterpenes. Particularly high enantioselectivity values in the asymmetric hydrogenation of 3,3-disubstituted allylic alcohols and related homoallylic alcohols have been achieved with Ir-phosphinomethyloxazoline catalysts. In contrast to other N,P-ligand complexes, which require weakly coordinating solvents, such as CH 2Cl2, these catalysts perform well in more ecofriendly THF or 2-MeTHF (see scheme; CODa =a 1,5-cyclooctadiene). Copyright
Palladium/chiral amine co-catalyzed enantioselective β-arylation of α,β-unsaturated aldehydes
Ibrahem, Ismail,Ma, Guangning,Afewerki, Samson,C?rdova, Armando
supporting information, p. 878 - 882 (2013/02/23)
Palladium and a simple chiral amine are used as co-catalysts for the enantioselective conjugate addition of aryl boronic acids to α,β-unsaturated aldehydes (see scheme). The synthetic utility of this co-catalyzed reaction was demonstrated in the short tot
Lipase-mediated resolution of substituted 2-aryl-propanols: Application to the enantioselective synthesis of phenolic sesquiterpenes
Serra, Stefano
, p. 619 - 628 (2011/07/08)
A comprehensive study of the lipase-mediated resolution of substituted 2-aryl-propanols is reported. The latter alcohols were submitted to the irreversible acetylation catalyzed either by PPL, CRL, or lipase PS. The enantioselectivity of these transformations was dependent on the type of lipase used. The type of substituents and particularly their position on the aromatic ring strongly affected the selectivity of the reaction. The experiments described prove that PPL is the more versatile lipase catalyzing the acetylation with an enantiomeric ratio (E) value that ranges from 1 up to 144, depending on the substrate used. Conversely, the same transformations were catalyzed by CRL and lipase PS with an enantiomeric ratio value, which is always less than 5. The remarkable behavior of PPL was exploited in the large scale resolution of some substituted 2-aryl-propanols whose enantiomeric forms are relevant building blocks in the enantioselective synthesis of phenolic sesquiterpenes. By these means, the synthesis of (S)-turmeronol B and the formal syntheses of (R)-curcumene, (R)-curcuphenol, (R)-xanthorrhizol, and (R)-curcuhydroquinone were accomplished.
Helical triskelion monophosphites as ligands in asymmetric catalysis
Reetz, Manfred T.,Guo, Hongchao,Jun-An, Ma.,Goddard, Richard,Mynott, Richard J.
supporting information; experimental part, p. 4136 - 4142 (2009/09/05)
Members of a new family of chiral triskelion P ligands, namely helical C3-symmetric monophos- phites P(OR)3, have been prepared in two steps Dy monoacylation of (R)- or (S)-1,1'-binaphthyl-2,2'-diol (BINOL) or diphenol using a carboxylic acid chloride followed Dy PCl3 phosphorylation. The most sterically hindered member of these monophosphites, derived from the compound accessible by monoacylation of BINOL using adamantane carboxylic acid chloride, has been characterized by X-ray crystallography and NMR spectroscopy as a single well-defined compound. It exists exclusively in the syn conformation, with a propeller-like (twisted) geometry resulting in helicity. Upon utilization of(R)- or (S)-BINOL in the two-step synthesis, the helicity proves to be P or M, respectively. When used as ligands in the Rh-catalyzed asymmetri c hydrogenation of prochiral homoallylic alcohols, these bulky helical ligands lead to respectable enantioselectivities (79-98percent ee). In contrast, the less sterically congested and more flexible BINOL-derived phenyl analogue exists in several conformeric forms, even in the crystal, and this leads to poor enantioselectivity in the model reactions (ee = 32percent). For the purpose of structural comparison, the analogous monophosphites derived from diphenol were also prepared and characterized. These compounds, again in contrast to the BINOL-derived adamantyl derivatives, occur in several different conformeric states.
Total synthesis of (R)- and (S)-turmerone and (7S,9R)-bisacumol by an efficient chemoenzymatic approach
Kamal, Ahmed,Shaheer Malik,Azeeza, Shaik,Bajee, Shaik,Shaik, Ahmad Ali
experimental part, p. 1267 - 1271 (2009/10/17)
An enantioselective synthesis of (R)-, (S)-turmerone and (7S,9R)-bisacumol is described. The enantiomerically pure key intermediates, a substituted butanoate ester and acid are utilized in the synthesis of both enantiomers of turmerone. The lipase catalyzed resolution studies of the acetate of bisacumol have been exploited towards the total synthesis of the naturally occurring cytotoxic sesquiterpene, (7S,9R)-bisacumol with high diastereoselectivity (94% de).
Enantioselective synthesis of (R)- and (S)-curcumene and curcuphenol: an efficient chemoenzymatic route
Kamal, Ahmed,Malik, M. Shaheer,Shaik, Ahmad Ali,Azeeza, Shaik
, p. 2547 - 2553 (2008/03/15)
An efficient enantioselective synthesis of curcumene and curcuphenol is described. The key intermediates, substituted butanoates 7a and 7b and their acids 8a and 8b are obtained in high enantiopurity (>99% ee) by a lipase-catalyzed kinetic resolution proc
Chiral benzyl centers through asymmetric catalysis. A three-step synthesis of (R)-(-)-α-curcumene via asymmetric hydrovinylation
Zhang, Aibin,RajanBabu
, p. 3159 - 3161 (2007/10/03)
(Chemical Equation Presented) A three-step, two-pot procedure involving asymmetric hydrovinylation followed by Suzuki-Miyaura reaction represents by far the shortest synthesis of this popular bisabolane. Other applications for the synthesis of similar com
New asymmetric construction of the benzylic quaternary stereogenic centre: An enantiocontrolled access to (-)-α-cuparenone
Kosaka, Takamitsu,Bando, Toshikazu,Shishido, Kozo
, p. 1167 - 1168 (2007/10/03)
An efficient and enantiocontrolled formal total synthesis of (-)-α-cuparenone has been accomplished by employing a new asymmetric construction methodology for formation of the benzylic quaternary stereogenic centre.
