114418-31-4Relevant academic research and scientific papers
Asymmetric Induction by a Nitrogen14N/15N Isotopomer in Conjunction with Asymmetric Autocatalysis
Matsumoto, Arimasa,Ozaki, Hanae,Harada, Shunya,Tada, Kyohei,Ayugase, Tomohiro,Ozawa, Hitomi,Kawasaki, Tsuneomi,Soai, Kenso
, p. 15246 - 15249 (2016/12/03)
Chirality arising from isotope substitution, especially with atoms heavier than the hydrogen isotopes, is usually not considered a source of chirality in a chemical reaction. An N2,N2,N3,N3-tetramethyl-2,3-butan
Reductive cleavage of acetals and ketals with 9-borabicyclo[3.3.1]nonane
Soderquist, John A.,Kock, Iveliz,Estrella, Maria E.
supporting information, p. 1076 - 1079 (2012/12/23)
The reductive cleavage of benzaldehyde acetals and acetophenone ketals with the air-stable crystalline 9-borabicyclo[3.3.1]-nonane dimer provides monobenzylated ether derivatives of diols and 1,2-oxygen-transposed β-phenethyl alcohols, respectively. The boron moiety is effectively recovered through simple procedures which involve convenient air-stable reagents and boron byproducts. The process is particularly selective for 1,3-diols giving the more substituted monobenzyl ether derivatives exclusively. With acetophenone ketals both reduction and elimination occur, permitting 9-BBN-H to hydroborate the resulting styrene to produce 1,2-oxygen-transposed β-phenethyl alcohols cleanly. Potential applications of this new process were illustrated with the synthesis of the hallucinogen, mescaline, and the analgesic, ibufenac.
Diastereoselectivity in the reduction of α-oxy- and α-amino-substituted acyclic ketones by polymethylhydrosiloxane
Nadkarni, Durgesh,Hallissey, James,Mojica, Carlos
, p. 594 - 596 (2007/10/03)
Diastereoselectivity in the reduction of α-alkoxy-, α-acyloxy-, and α-alkylamino-substituted ketones with polymethylhydrosiloxane (PMHS) in the presence of fluoride ion catalysis was investigated. High syn-selectivity was observed in the reduction of α-alkoxy, α-acyloxy, and α-dialkylamino ketones. Reduction of α-monoalkylamino ketone proceeded in anti-selective manner with moderate selectivity. The observed selectivity is explained based on Felkin-Anh and Cram-chelate models.
Hydrogenation of α-Keto Ethers: Dynamic Kinetic Resolution with a Heterogeneous Modified Catalyst and a Heterogeneous Base
Studer, Martin,Blaser, Hans-Ulrich,Burkhardt, Stephan
, p. 511 - 515 (2007/10/03)
The first successful example of the asymmetric hydrogenation of substituted α-keto ethers with Cinchona-modified Pt/Al2O3 is reported. In the absence of an additional base, kinetic resolution of the racemic starting material was observed with high diastereoselectivity and ee's up to 98% at conversions of a strong reaction acceleration but racemic product. Immobilization of OH- on solid ion exchangers resulted in the desired dynamic kinetic resolution, and ee's of >80% were obtained at >95% conversion. These effects are rationalized on the basis of a simple kinetic and structural model.
Chelation-controlled reduction of α- and β-oxygenated ketones with lithium tri-n-butylborohydride
Faucher, Anne-Marie,Brochu, Christian,Landry, Serge R.,Duchesne, Isabelle,Hantos, Susanne,Roy, Amelie,Myles, Andrew,Legault, Claude
, p. 8425 - 8428 (2007/10/03)
Lithium tri-n-butyl borohydride showed high selectivity in the reduction of α- and β-oxygenated ketones, giving a preponderance of the chelation controlled products.
Methylaluminum bis(4-substituted-2,6-di-tert-butylphenoxide) as an efficient nonchelating Lewis acid: Application to asymmetric Diels-Alder reaction and diastereoselective alkylation to alkoxy carbonyl substrates
Maruoka, Keiji,Oishi, Masataka,Shiohara, Kei,Yamamoto, Hisashi
, p. 8983 - 8996 (2007/10/02)
The exceptionally bulky methylaluminum bis(4-substituted-2,6-di-tert-butylphenoxide) such as MAD or MABR can be successfully utilized as a highly efficient nonchelating Lewis acid for achieving high stereoselectivity in 1,n asymmetric induction in cyclic
First direct NMR spectroscopic observation of a Cram-chelate involving a chiral α-alkoxy aldehyde
Reetz, Manfred T.,Raguse, Burkhard,Seitz, Thomas
, p. 8561 - 8568 (2007/10/02)
The reaction of CH3TiCl3 with 2-benzyloxy propanal 10 at low temperatures in CD2Cl2 leads to the formation of two diastereomeric Cram-type chelates 13a/13b which can be observed directly by 13C-NMR spectroscopy. The octahedral chelates undergo C---C bond formation with first order kinetics, suggesting intramolecular 1,3 methyl transfer. Crossover experiments are unsuitable for definitive proof of intramolecularity due to ligand exchange reactions prior to Grignard-type addition.
Diastereoselective addition of organomanganese compounds to α-alkoxysubstituted propanals
Kasatkin, A. N.,Biktimirov, R. Kh.,Podlipchuk, I. P.,Sultanmuratova, V. R.,Tolstikov, G. A.
, p. 161 - 165 (2007/10/02)
Reactions of organomanganese compounds R1MnI (R1 = Ph, 4-MeC6H4, Me, Bu, n-C7H15, BuCC, PhCC),prepared from R1Li and MnI2 in Et2O, with aldehydes MeCH(OR2)CHO (R2 = CH2Ph, CH2OMe, CH2OCH2Ph) afford threo-alcohols MeCH(OR2)CH(OH)R1 with high diastereoselec
STEREOCONTROLLED ONE-POT CONVERSIONS OF α-ALKOXY ESTERS TO SYN- AND ANTI-1,2-DIOL DERIVATIVES
Burke, Steven D.,Deaton, David N.,Olsen, Robert J.,Armistead, David M.,Blough, Bruce E.
, p. 3905 - 3906 (2007/10/02)
Complementary one-pot methods for the sequential addition of carbon and hydride nucleophiles to α-alkoxy esters leading to syn or anti mono-protected vicinal glycol derivatives are described.
ZnBr2-MEDIATED HIGHLY DIASTEREOSELECTIVE ADDITION OF GRIGNARD REAGENTS TO α-BENZYLOXY ALDEHYDES
Asami, Masatoshi,Kimura, Rieko
, p. 1221 - 1222 (2007/10/02)
α-Benzyloxy aldehydes reacted with Grignard reagents in the presence of ZnBr2 to afford vicinal syn-diol derivatives with high diastereoselectivity.
