86423-92-9Relevant academic research and scientific papers
Asymmetric hydrogenation of allylic alcohols using ir?N,P-Complexes
Li, Jia-Qi,Liu, Jianguo,Krajangsri, Suppachai,Chumnanvej, Napasawan,Singh, Thishana,Andersson, Pher G.
, p. 8342 - 8349 (2018/05/23)
In this study, a series of γ,γ-disubstituted and β,γ-disubstituted allylic alcohols were prepared and successfully hydrogenated using suitable N,P-based Ir complexes. High yields and excellent enantioselectivities were obtained for most of the substrates studied. This investigation also revealed the effect of the acidity of the N,P?Ir-complexes on the acid-sensitive allylic alcohols. DFT ΔpKa calculations were used to explain the effect of the N,P-ligand on the acidity of the corresponding Ir-complex. The selectivity model of the reaction was used to accurately predict the absolute configuration of the hydrogenated alcohols.
Systematic comparison of sets of 13C NMR spectra that are potentially identical. Confirmation of the configuration of a cuticular hydrocarbon from the cane beetle antitrogus parvulus
Basar, Norazah,Damodaran, Krishnan,Liu, Hao,Morris, Gareth A.,Sirat, Hasnah M.,Thomas, Eric J.,Curran, Dennis P.
, p. 7477 - 7490 (2014/10/15)
A systematic process is introduced to compare 13C NMR spectra of two (or more) candidate samples of known structure to a natural product sample of unknown structure. The process is designed for the case where the spectra involved can reasonably
Total synthesis, proof of absolute configuration, and biosynthetic origin of stylopsal, the first isolated sex pheromone of strepsiptera
Lagoutte, Roman,?ebesta, Petr,Jiro?, Pavel,Kalinová, Blanka,Jiro?ová, Anna,Straka, Jakub,?erná, Kate?ina,?obotník, Jan,Cva?ka, Josef,Jahn, Ullrich
supporting information, p. 8515 - 8524 (2013/07/11)
The asymmetric total synthesis of the diastereomers of stylopsal establishes the absolute configuration of the first reported sex pheromone of the twisted-wing parasite Stylops muelleri as (3R,5R,9R)-trimethyldodecanal. The key steps for the diastereo- and enantiodivergent introduction of the methyl groups are two different types of asymmetric conjugate addition reactions of organocopper reagents to α,β-unsaturated esters, whereas the dodecanal skeleton is assembled by Wittig reactions. The structure of the natural product was confirmed by chiral gas chromatography (GC) techniques, GC/MS and GC/electroantennography (EAD) as well as field tests. An investigation into the biosynthesis of the pheromone revealed that it is likely to be produced by decarboxylation of a 4,6,10-trimethyltridecanoic acid derivative, which was found in substantial amounts in the fat body of the female, but not in the host bee Andrena vaga. This triple-branched fatty acid precursor thus seems to be biosynthesized de novo through a polyketide pathway with two consecutive propionate-propionate-acetate assemblies to form the complete skeleton. The simplified, motionless and fully host-dependent female exploits a remarkable strategy to maximize its reproductive success by employing a relatively complex and potent sex pheromone. Love at first.i??-smell: An asymmetric total synthesis, gas chromatographic analyses, and field tests confirm the structure of the first isolated sex pheromone of a twisted-wing parasite Stylops muelleri (see figure). Its biosynthetic origin and complexity demonstrate the considerable efforts undertaken by the motionless and fully host-dependant female to attract the very short-lived free-living male, thus securing success in the perpetuation of the species. Copyright
The organocatalytic addition of bis(arylsulfonyl)methane to α,β-unsaturated aldehydes and the synthesis of optically-enriched 3-methyl-alkanols
Garcia Ruano, Jose Luis,Marcos, Vanesa,Aleman, Jose
supporting information; experimental part, p. 4435 - 4437 (2009/12/29)
An indirect organocatalytic method for the β-methylation of α,β-unsaturated aldehydes that involves the addition of bis(arylsulfonyl)methane catalyzed by prolinol derivatives and further elimination of the chameleonic sulfonyl groups is presented. The Roy
Asymmetric conjugate addition for the preparation of syn-1,3-dimethyl arrays: Synthesis and structure elucidation of capensifuranone
Williams, David R.,Nold, Andrea L.,Mullins, Richard J.
, p. 5374 - 5382 (2007/10/03)
The synthesis of capensifuranone (1) has been achieved by the application of developments for asymmetric conjugate addition reactions of organocopper reagents with nonracemic N-enoyl-4-phenyl-1,3-oxazolidinones for the preparation of 1,3-syn-dimethyl arra
Toward a total synthesis of okilactomycin. 2. A metathesis-based approach to the heavily functionalized cyclohexane ring
Boulet, Serge L.,Paquette, Leo A.
, p. 895 - 900 (2007/10/03)
An attempt to access in an enantioselective fashion, a highly substituted cyclohexane as required for the northeastern sector of okilactomycin is described. The application of Oppolzer's sultam chemistry, involving in particular an optically and chemicall
Enantioselective carbometalation of cinnamyl derivatives: New access to chiral disubstituted cyclopropanes - Configurational stability of benzylic organozinc halides
Norsikian, Stephanie,Marek, Ilan,Klein, Sophie,Poisson, Jean F.,Normant, Jean F.
, p. 2055 - 2068 (2007/10/03)
A stoichiometric or catalytic amount of (-)-sparteine can serve asa promoter for the enantioselective carbolithiation of cinnamyl derivatives by primary and secondary organolithium compounds. The enantiofacial choice of the addition reaction is dependent on the stereochemistry of the initial double bond. The resulting benzylic organolithium compounds can be derivatized to a linear phenylated chain that bears two contiguous stereogenic centers with given configurations. The use of the dimethyl acetal of the (E)-cinnamyl alcohol allows the highest enantioselective carbolithiation and by simply warming the reaction mixture to room temperature, the resulting benzylic organo-lithium intermediate undergoes a 1,3-elimination to give the chiral disubstituted cyclopropane in high enantiomeric excess (90-95% ee). Another significant finding is the observation that the Li-Zn transmetalation in a benzylic species occurs with inversion of configuration, and the corresponding acyclic benzylic zinc halides have observable configurational stability at - 30°C.
Sterically constrained tricyclic 2-oxazolidinone as excellent chiral auxiliary
Nakamura, Taiju,Hashimoto, Noriaki,Ishizuka, Tadao,Kunieda, Takehisa
, p. 559 - 562 (2007/10/03)
A new class of conformationally rigid 2-oxazolidinones with effectively bulky substituents, derived from the [4+2] cycloadduct of cyclopentadiene and a-oxazolone, serve as extremely powerful chiral auxiliaries for asymmetric alkylations, Diels-Alder reactions and conjugate addition reactions.
Enantioselective carbolithiation of β-alkylated styrene
Norsikian, Stephanie,Marek, Ilane,Normant, Jean-F.
, p. 7523 - 7526 (2007/10/03)
Stoichiometric or catalytic amounts of (-) sparteine serve as promoter for enantioselective carbolithiation of β-alkylated, non functionalized styrene.
Camphorsulfonamide-Shielded, Asymmetric 1,4-Additions and Enolate Alkylations; Synthesis of a Southern Corn Rootworm Pheromone
Oppolzer, Wolfgang,Dudfield, Philip,Stevenson, Thomas,Godel, Thierry
, p. 212 - 215 (2007/10/02)
Using readily accessible 10-sulfonamido-isoborneols as regenerable, chiral auxiliaries, highly face-selective C-C-bond formations at Cα and Cβ of carboxylates could be conveniently achieved.Thus, conjugated additions of RCu to enoates (1->2) furnished, after saponification, β-substituted carboxylic acids 3 in 94-98 percent e.e.Similarly, propionates 12 yielded after deprotonation, enolate alkylation, and reductive ester cleveage the (R)-alcohols 15 in 78-98 percent e.e.The acid (+)-3e was converted to the pheromone (-)-11.
