121617-17-2Relevant articles and documents
Preparation of β-hydroxyesters from isoxazolines. A selective Ni 0bpy-catalyzed electrochemical method
Caetano, Viviane F.,Demnitz, F.W. Joachim,Diniz, Flamarion B.,Mariz Jr., Ronaldo M.,Navarro, Marcelo
, p. 8217 - 8220 (2003)
An electrocatalytic method for the reductive N-O cleavage of isoxazolines is described. Ni0bpy, generated in situ, was used to promote selective ring opening of 3-methoxy-5-phenylisoxazoline (1a) and 3-methoxy-[4,5]cyclohexylisoxazoline (1b). DMF and NaI were used as solvent and supporting electrolyte, and β-hydroxyesters 2a and 2b were obtained in high yields respectively, after acid hydrolysis. β-Hydroxynitriles 3a and 3b were also identified as side products.
Reformatsky reactions with SmI2 in catalytic amount
Orsini, Fulvia,Lucci, Elvira Maria
, p. 1909 - 1911 (2005)
A substoichiometric protocol for Reformatsky-type addition of α-haloesters, α-haloketones, α-halonitriles, and α-halophosphonates to carbonyl compounds has been developed. β-Hydroxyesters and β-hydroxynitriles were obtained in good to excellent yields.
One step conversion of highly dipolarophilic olefins to α-hydroxy-β-cyanoadducts with metal fulminate
You, Zhengqing,Lee, Henry Joung
, p. 1165 - 1168 (1996)
Olefins conjugated with carbonyl, carboxylic ester, and phenyl groups as well as highly strained non-conjugated olefin norbornylene were converted to their corresponding α-hydroxy-β-cyanoadducts by treatment with mercuric fulminate and lithium bromide. Th
-
Kaiser,E.M.,Hauser,C.R.
, p. 3402 - 3404 (1968)
-
Steric vs. electronic effects in the Lactobacillus brevis ADH-catalyzed bioreduction of ketones
Rodriguez, Cristina,Borzecka, Wioleta,Sattler, Johann H.,Kroutil, Wolfgang,Lavandera, Ivan,Gotor, Vicente
, p. 673 - 681 (2014)
Lactobacillus brevis ADH (LBADH) is an alcohol dehydrogenase that is commonly employed to reduce alkyl or aryl ketones usually bearing a methyl, an ethyl or a chloromethyl as a small ketone substituent to the corresponding (R)-alcohols. Herein we have tested a series of 24 acetophenone derivatives differing in their size and electronic properties for their reduction employing LBADH. After plotting the relative activity against the measured substrate volumes we observed that apart from the substrate size other effects must be responsible for the activity obtained. Compared to acetophenone (100% relative activity), other small substrates such as propiophenone, α,α, α-trifluoroacetophenone, α-hydroxyacetophenone, and benzoylacetonitrile had relative activities lower than 30%, while medium-sized ketones such as α-bromo-, α,α-dichloro-, and α,α-dibromoacetophenone presented relative activities between 70% and 550%. Moreover, the comparison between the enzymatic activity and the obtained final conversions using an excess or just 2.5 equiv. of the hydrogen donor 2-propanol, denoted again deviations between them. These data supported that these hydrogen transfer (HT) transformations are mainly thermodynamically controlled. For instance, bulky α-halogenated derivatives could be quantitatively reduced by LBADH even employing 2.5 equiv. of 2-propanol independently of their kinetic values. Finally, we found good correlations between the IR absorption band of the carbonyl groups and the degrees of conversion obtained in these HT processes, making this simple method a convenient tool to predict the success of these transformations. The Royal Society of Chemistry.
-
Wul'fson,Winograd
, (1956)
-
Formation of carbanions from carboxylate ions bearing electron-withdrawing groups via photoinduced decarboxylation: Addition of generated carbanions to benzaldehyde
Kumagai, Yuta,Naoe, Takashi,Nishikawa, Keisuke,Osaka, Kazuyuki,Morita, Toshio,Yoshimi, Yasuharu
, p. 1668 - 1671 (2015)
The photoinduced decarboxylation of carboxylate ions bearing electron-withdrawing groups using biphenyl and 1,4-dicyanonaphthalene leads to the efficient generation of carbanions under mild conditions. The efficiency of the carbanion generation is strongl
Highly regioselective conversion of epoxides to β-hydroxy nitriles with cyanide exchange resin
Tamami,Iranpoor,Rezaei
, p. 3153 - 3157 (2003)
A simple and regioselective method is described for the efficient conversion of epoxides to β-hydroxy nitriles using Amberlite IRA-400 supported cyanide. The reactions occur in the absence of catalyst and furnish the corresponding β-hydroxy nitriles in high yields.
Mukaiyama addition of (trimethylsilyl)acetonitrile to dimethyl acetals mediated by trimethylsilyl trifluoromethanesulfonate
Downey, C. Wade,Lee, Alice Y.-K.,Goodin, John R.,Botelho, Courtney J.,Stith, William M.
, p. 3496 - 3499 (2017)
(Trimethylsilyl)acetonitrile reacts smoothly with dimethyl acetals in the presence of stoichiometric trimethylsilyl trifluoromethanesulfonate (TMSOTf) to yield β-methoxynitriles. The ideal substrates for this reaction are acetals derived from aromatic aldehydes. Elimination to the corresponding α,β-unsaturated nitriles is observed as the major product in the case of electron-rich acetals. A mechanistic hypothesis that includes isomerization of the silylnitrile to a nucleophilic N-silyl ketene imine is presented.
ADDITONS OF ANIONIC NUCLEOPHILES TO CARBONYL COMPOUNDS : CATION AND ELECTROPHILE NATURE INFLUENCE ON IONIC ASSOCIATION VS CARBONYL COMPLEXATION CONTROL
Loupy, A.,Roux-Schmitt, M. C.,Seyden-Penne, J.
, p. 1685 - 1688 (1981)
The raction of benzaldehyde with LiCH2CN in THF is controlled by carbonyl complexation while with KCH2CN the reaction is controlled by ionic association.In the reaction of m.Cl.C6H4CHCN(1-)/Li(1+) with substituted benzaldehydes, carbonyl complexation prevails with p.CH3OC6H4CHO while ionic association dominates with PhCHO and p.CNC6H4CHO.
Chiral Benzothiophene Synthesis via Enantiospecific Coupling of Benzothiophene S-Oxides with Boronic Esters
Aggarwal, Varinder K.,Noble, Adam,Sang, Ruocheng
supporting information, p. 25313 - 25317 (2021/11/09)
Benzothiophenes are valuable heterocycles that are widely used in medicines, agrochemicals, and materials science. Herein, we report a general method for the synthesis of enantioenriched 2,3-disubstituted benzothiophenes via a transition-metal-free C2-alkylation of benzothiophenes with boronic esters. The reactions utilize benzothiophene S-oxides in lithiation-borylations to generate intermediate arylboronate complexes, and subsequent Tf2O-promoted S?O bond cleavage to trigger a Pummerer-type 1,2-metalate shift, which gives the coupled products with complete enantiospecificity. Primary, secondary and tertiary alkyl boronic esters and aryl boronic esters are successfully coupled with a range of C3-substituted benzothiophenes. Importantly, this transformation does not require the use of C3 directing groups, therefore it overcomes a major limitation of previously developed transition-metal-mediated C2 alkylations of benzothiophenes.
Biocatalytic asymmetric ring-opening of dihydroisoxazoles: a cyanide-free route to complementary enantiomers of β-hydroxy nitriles from olefins
Asano, Yasuhisa,Zheng, Daijun
supporting information, p. 4930 - 4936 (2020/08/25)
By combination of the cyanide-free synthesis of chiral nitriles and the Kemp elimination reaction catalyzed by aldoxime dehydratases, we herein report a new application of aldoxime dehydratase in the asymmetric ring-opening of 5-sub-4,5-dihydroisoxazoles
