- Reductive Coupling of Aromatic Aldehydes and Ketones under Electrochemical Conditions
-
Reductive coupling of o-substituted carbonyl compounds and m-substituted carbonyl compounds by the direct transfer of electron to carbonyl group respectively gave 1-(4-(1-hydroxy-1-phenylethyl/methyl)phenyl)ethanones/methanones and 2,3-bis(3-substitutedph
- Li, Qian-Yu,Swaroop, Toreshettahally R.,Wang, Heng Shan,Wang, Zi-Qiang
-
-
- A Direct Br?nsted Acid-Catalyzed Azidation of Benzhydrols and Carbohydrates
-
Benzhydryl alcohols were converted into their corresponding diarylazidomethane analogues using azidotrimethylsilane (TMSN3) in the presence of a catalytic amount of a Br?nsted acid HBF4·OEt2. The azidation reactions proceeded in high yields and demonstrated excellent functional group tolerance to electron-donating and electron-withdrawing substituents. In addition, a range of unprotected functional groups including amine, amide, aldehyde and alcohol were well-tolerated. Furthermore, this methodology was successfully applied to carbohydrates for the preparation of the corresponding azide derivatives.
- Regier, Jeffery,Maillet, Robert,Bolshan, Yuri
-
p. 2390 - 2396
(2019/04/14)
-
- Selective mono addition of aryllithiums to dialdehydes by micromixing
-
Micromixing enables highly selective mono addition of aryllithiums to dialdehydes. Because the unchanged formyl group in the products can be used for further transformations, the present approach serves as a powerful method for protecting-group-free synthesis.
- Nagaki, Aiichiro,Yamashita, Hiroki,Takahashi, Yusuke,Ishiuchi, Satoshi,Imai, Keita,Yoshida, Jun-Ichi
-
supporting information
p. 71 - 73
(2018/01/26)
-
- Chemoselective hydrogen peroxide oxidation of allylic and benzylic alcohols under mild reaction conditions catalyzed by simple iron-picolinate complexes
-
Chemoselective oxidation of allylic alcohols to α,β-unsaturated carbonyl compounds proceeded efficiently using hydrogen peroxide with iron-picolinate catalysts. The in situ generated [Fe(Me-Pic)3] (Me-Pic = 6-methylpicolinate) catalyzed oxidation of the alcohol moiety of primary allylic alcohols while the [Fe(Pic)3] (Pic = picolinate) and [Fe(Me-Pic)2(Pic)] did not show sufficient catalytic activity. This journal is
- Tanaka, Shinji,Kon, Yoshihiro,Nakashima, Takuya,Sato, Kazuhiko
-
p. 37674 - 37678
(2014/12/11)
-
- Chemoselective hydrogen peroxide oxidation of allylic and benzylic alcohols under mild reaction conditions catalyzed by simple iron-picolinate complexes
-
Chemoselective oxidation of allylic alcohols to α,β-unsaturated carbonyl compounds proceeded efficiently using hydrogen peroxide with iron-picolinate catalysts. The in situ generated [Fe(Me-Pic)3] (Me-Pic = 6-methylpicolinate) catalyzed oxidation of the alcohol moiety of primary allylic alcohols while the [Fe(Pic)3] (Pic = picolinate) and [Fe(Me-Pic)2(Pic)] did not show sufficient catalytic activity. the Partner Organisations 2014.
- Tanaka, Shinji,Kon, Yoshihiro,Nakashima, Takuya,Sato, Kazuhiko
-
p. 37674 - 37678
(2014/11/07)
-
- Methodology for in situ protection of aldehydes and ketones using trimethylsilyl trifluoromethanesulfonate and phosphines: Selective alkylation and reduction of ketones, esters, amides, and nitriles
-
A methodology for selective transformations of ketones, esters, Weinreb amides, and nitriles in the presence of aldehydes has been developed. The use of a combination of PPh3-trimethylsilyl trifluoromethanesulfonate (TMSOTf) promotes selective transformation of aldehydes to their corresponding, temporarily protected, O,P-acetal type phosphonium salts. Because, hydrolytic work-up following ensuing reactions of other carbonyl moieties in the substrates liberates the aldehyde moiety, a sequence involving aldehyde protection, transformation of other carbonyl groups, and deprotection can be accomplished in a one-pot manner. Furthermore, the use of PEt3 instead of PPh 3 enables ketones to be converted in situ to their corresponding O,P-ketal type phosphonium salts and, consequently, selective transformations of esters, Weinreb amides, and nitriles in the presence of ketones can be performed. This methodology is applicable to various dicarbonyl compounds, including substrates that possess heteroaromatic skeletons and hydroxyl protecting groups.
- Yahata, Kenzo,Minami, Masaki,Yoshikawa, Yuki,Watanabe, Kei,Fujioka, Hiromichi
-
p. 1298 - 1307
(2014/01/06)
-
- METHOD FOR SYNTHESIS OF SECONDARY ALCOHOLS
-
A method for synthesis of secondary alcohols is provided for pharmaceutical secondary alcohol by addition of organoboronic acids with aldehydes in presence of the cobalt ion and bidentate ligands as the catalyst. In addition, an enantioselective synthesis method for secondary alcohols is also herein provided in the present invention. The present invention has advantages in using less expensive cobalt ion and commercially available chiral ligands as the catalyst, wide scope of organoboronic acids and aldehydes compatible with this catalytic reaction and achieving excellent yields and/or enantiomeric excess.
- -
-
Page/Page column 2
(2012/06/16)
-
- Synthesis and structure-activity relationships of benzophenone-bearing diketopiperazine-type anti-microtubule agents
-
KPU-105 (4), a potent anti-microtubule agent that contains a benzophenone was derived from the diketopiperazine-type vascular disrupting agent (VDA) plinabulin 3, which displays colchicine-like tubulin depolymerization activity. To develop derivatives wit
- Hayashi, Yoshio,Yamazaki, Yuri,Sumikura, Makiko,Masuda, Yurika,Hayashi, Yoshiki,Yasui, Hiroyuki,Kiso, Yoshiaki,Chinen, Takumi,Usui, Takeo,Yakushiji, Fumika,Potts, Barbara,Neuteboom, Saskia,Palladino, Michael,Lloyd, George Kenneth
-
p. 4279 - 4289
(2012/09/08)
-
- Palladium-imidazolinium carbene-catalyzed arylation of aldehydes with arylboronic acids in water
-
The catalytic arylation of aldehydes with arylboronic acids in only water was found to be achieved using the palladium/thioether-imidazolinium chloride system in good to excellent yields. This catalytic process showed high tolerance for a broad range of substrates, giving a variety of carbinol derivatives with 2.0-3.0 mol % of the catalyst.
- Kuriyama, Masami,Ishiyama, Natsuki,Shimazawa, Rumiko,Onomura, Osamu
-
experimental part
p. 6814 - 6819
(2010/10/02)
-
- Cobalt-catalyzed addition reaction of organoboronic acids with aldehydes: Highly enantioselective synthesis of diarylmethanols
-
Predicted outcomes: The addition reaction of organoboronic acids with aldehydes in the presence of K2CO3 catalyzed by CoI 2/ACHTUNGRE(R,R)-BDPP gives chiral secondary alcohols in excellent yields with 90-99 % enantiomeric excess (see scheme; (R,R)-BDPP = (2R,4R)-(+)-2,4-bis(diphenyl-phosphino)pentane). This method provides an alternative to prepare an R and S enantiomeric pair by using the same chiral ligand and allows the stereochemical outcome of the reaction to be predicted.
- Karthikeyan, Jaganathan,Jeganmohan, Masilamani,Cheng, Chien-Hong
-
supporting information; experimental part
p. 8989 - 8992
(2010/10/02)
-
- Copper(II) acetate-catalyzed addition of arylboronic acids to aromatic aldehydes
-
A novel copper-catalyzed protocol for the synthesis of carbinol derivatives has been developed. In the presence of copper(II) acetate and dppf, carbinol derivatives were prepared by the addition of arylboronic acids to aromatic aldehydes in good to excellent yields. Moreover, the rigorous exclusion of air or moisture is not required in these transformations.
- Zheng, Hanmei,Zhang, Qiang,Chen, Jiuxi,Liu, Miaochang,Cheng, Shuanghua,Ding, Jinchang,Wu, Huayue,Su, Weike
-
experimental part
p. 943 - 945
(2009/06/20)
-
- Oxidation of alcohols with nitroxyl radical resins under two-phase conditions
-
The oxidation of alcohols to carbonyl compounds such as aldehydes and ketones was studied using potassium hexacyanoferrate(III) mediated by nitroxyl radical polystyrene resins as catalyst under organic-aqueous two-phase conditions. Primary alcohols are readily oxidized to the corresponding aldehydes in excellent yield with no overoxidation to carboxylic acids. Secondary alcohols are converted to the corresponding ketones with a much lower efficiency. Oxidative cyclization of 1,4- and 1,5-diols to γ- and δ-lactones, respectively, proceeded nicely. Georg Thieme Verlag Stuttgart.
- Kashiwagi, Yoshitomo,Ikezoe, Hiroshi,Ono, Tetsuya
-
-
- Pentamethylcyclopentadienide in organic synthesis: Nucleophilic addition of lithium pentamethylcyclopentadienide to carbonyl compounds and carbon-carbon bond cleavage of the adducts yielding the parent carbonyl compounds
-
Lithium pentamethylcyclopentadienide (C5Me5Li, Cp*Li) reacted with aromatic aldehyde to provide the corresponding carbinol in excellent yield. The carbinol returns to the parent aldehyde and pentamethylcyclopentadiene upon exposure to acid or due to heating. Chlorodimethylaluminum is essential as an additive to attain the nucleophilic addition of Cp*Li to aliphatic aldehyde. The carbinol derived from aliphatic aldehyde returns to the parent aldehyde and pentamethylcyclopentadiene by the action of a catalytic amount of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The reversible addition/elimination of the Cp* group can represent a protection of aldehyde. Mechanistic details of the carbon-carbon bond cleavage are also disclosed.
- Uemura, Minoru,Yagi, Kazunari,Iwasaki, Masayuki,Nomura, Kenichi,Yorimitsu, Hideki,Oshima, Koichiro
-
p. 3523 - 3535
(2007/10/03)
-
- Pentamethylcyclopentadienide in organic synthesis: Nucleophilic addition of lithium pentamethylcyclopentadienide to aromatic aldehydes and carbon-carbon bond cleavage of the adducts affording the parent aldehydes
-
Treatment of aromatic aldehyde with lithium pentamethylcyclopentadienide provided the corresponding carbinol in excellent yield. The carbinol returns to the parent aldehyde and pentamethylcyclopentadiene upon exposure to an acid or due to heating. The com
- Yagi, Kazunari,Yorimitsu, Hideki,Oshima, Koichiro
-
p. 4831 - 4833
(2007/10/03)
-
- Reductive lithiation of 1,3-dimethyl-2-arylimidazolidines
-
Naphthalene catalyzed lithiation of 1,3-dimethyl-2-phenylimidazolidine led to cleavage of the benzylic carbon-nitrogen bond, with formation of an intermediate dianion. Under similar conditions, 1,3-dimethyl-2-(4-chlorophenyl) imidazolidine underwent regioselective cleavage of the aromatic carbon-chlorine bond, leading to a 4-formylphenyllithium equivalent, whilst 1,3-dimethyl-2-(4- methoxymethylphenyl)imidazolidine underwent regioselective cleavage of the benzylic carbon-oxygen bond, leading to a 4-formylbenzyllithium equivalent.
- Azzena, Ugo,Dettori, Giovanna,Pisano, Luisa,Siotto, Immacolata
-
p. 3177 - 3182
(2007/10/03)
-
- Oxidation of alcohols with nitroxyl radical under polymer-supported two-phase conditions
-
The oxidation of alcohols to carbonyl compounds was studied using potassium hexacyanoferrate(III) mediated by nitroxyl radical as the catalyst under polymer-supported organic-aqueous two-phase conditions. Primary alcohols are readily oxidized to the corresponding aldehydes in excellent yield with no over-oxidation to carboxylic acids. Secondary alcohols are converted to the corresponding ketones with a much lower efficiency. The oxidation reactions of primary alcohols in the presence of secondary alcohols is strongly favored. Primary-secondary diols are selectively transformed into hydroxy aldehydes with small amounts of ketoaldehydes, the amount of isomeric keto alcohols remaining is less than 1%.
- Yoshitomo, Kashiwagi,Chiba, Shinya,Anzai, Jun-ichi
-
p. 1545 - 1549
(2007/10/03)
-
- Phenyl-Carbonyl Coupling Reactions Promoted by Samarium Diiodide and Hexamethylphosphoramide
-
By mediation of samarium diiodide and hexamethylphosphoramide, benzaldehydes and acetophenones underwent self- and cross-couplings to give the products having linkages at the para-carbons of phenyl rings and the carbonyl groups. The phenyl-carbonyl coupling of 2,5-dimethoxybenzaldehyde generated a Sm(III)-enolate intermediate, which was trapped by alkyl halides in a stereospecific manner to give uncommon 1,4-dialkyl-2,5-cyclohexadiene-1-carboxaldehydes. The benzaldehydes bearing tethered carbonyl chains proceeded with intramolecular phenyl-carbonyl couplings to afford fused benzocycles.
- Shiue, Jiann-Shyng,Lin, Mei-Huey,Fang, Jim-Min
-
p. 4643 - 4649
(2007/10/03)
-
- Efficient and highly selective oxidation of Primary alcohols to aldehydes by N-chlorosuccinimide mediated by oxoammonium salts
-
2,2,6,6-Tetramethyl-1-piperidinyloxy catalyzes efficient oxidation of primary alcohols to aldehydes by N-chlorosuccinimide, in a biphasic dichloromethane - aqueous pH 8.6 buffer system in the presence of tetrabutylammonium chloride. Aliphatic, benzylic, and allylic alcohols are readily oxidized with no overoxidation to carboxylic acids. Secondary alcohols are oxidized to ketones with a much lower efficiency. Very high chemoselectivities are observed when primary alcohols are oxidized in the presence of secondary ones. Primary - secondary diols are selectively transformed into hydroxy aldehydes, with, in some cases, no detectable formation of the isomeric keto alcohols.
- Einhorn, Jacques,Einhorn, Cathy,Ratajczak, Fabien,Pierre, Jean-Louis
-
p. 7452 - 7454
(2007/10/03)
-
- Samarium diiodide / hexamethylphosphoramide promoted dimerization of benzaldehydes
-
Benzaldehyde, its ortho- and meta-substituted derivatives and acetophenone underwent dimerization reactions on treatment with samarium(II) iodide in the presence of HMPA. Intramolecular phenyl-carbonyl coupling reactions were similarly carried out.
- Shiue, Jiann-Shyng,Lin, Chun-Cheng,Fang, Jim-Min
-
p. 335 - 338
(2007/10/02)
-
- CHEMOSELECTIVE REDUCTION OF ALDEHYDES WITH TETRA-n-BUTYLAMMONIUM TRIACETOXYBOROHYDRIDE
-
Aldehydes, but not ketones, are smoothly reduced to alcohols by tetra-n-butylammonium triacetoxyborohydride in refluxing benzene.
- Nutaitis, Charles F.,Gribble, Gordon W.
-
p. 4287 - 4290
(2007/10/02)
-