39212-15-2Relevant academic research and scientific papers
Dirhodium(ii)/P(t-Bu)3 catalyzed tandem reaction of α,β-unsaturated aldehydes with arylboronic acids
Ma, Ziling,Wang, Yuanhua
, p. 7470 - 7476 (2018)
Phosphine ligated dirhodium(ii) acetate is advocated as a catalyst for the synthesis of aryl alkyl ketones by the tandem reaction of α,β-unsaturated aromatic or aliphatic aldehydes with arylboronic acids. This tandem procedure included arylation followed by the isomerization reaction. This method exhibits good functional group tolerance and has a broad substrate scope. With the conjugated aldehydes, the one-step synthesis of γ,δ-unsaturated ketones was realized through this reaction. It is noteworthy that the length of the Rh-P bond is an important factor affecting catalytic reactions. The comparative analysis of the crystal structures of axially alkylphosphane and arylphosphane ligated dirhodium(ii) acetate revealed that the shorter Rh-P bond length favors the isomerization process as compared to the longer one. In addition, the dirhodium(ii) compound can be recovered after the completion of the reaction.
Direct Reduction of Allylic Alcohols Using Isopropanol as Reductant
Sai, Masahiro
, p. 3482 - 3487 (2018/09/14)
The lithium cation-catalyzed direct reduction of allylic alcohols to alkenes using isopropanol as a hydride donor was developed. The hydride transfer of the in situ-generated lithium isopropoxide to an allylic cation is the key process in this transformation. The reaction generates only water and acetone as byproducts, which highlights the synthetic utility of this method. (Figure presented.).
Copper-catalyzed oxidative transformation of secondary alcohols to 1,5-disubstituted tetrazoles
Rokade, Balaji V.,Gadde, Karthik,Prabhu, Kandikere Ramaiah
, p. 946 - 950 (2014/04/03)
A mild and convenient oxidative transformation of secondary alcohols to 1,5-disubstituted tetrazoles is uncovered by employing trimethylsilyl azide (TMSN3) as a nitrogen source in the presence of a catalytic amount of copper(II) perchlorate hexahydrate [Cu(ClO4)2 .6 H2O] (5 mol%) and 2,3-dichloro-5,6-dicyano-para- benzoquinone (DDQ) (1.2 equiv.) as an oxidant. This reaction is performed under ambient conditions and proceeds through C-C bond cleavage.
Zinc phthalocyanine with PEG-400 as a recyclable catalytic system for selective reduction of aromatic nitro compounds
Sharma, Upendra,Kumar, Neeraj,Verma, Praveen Kumar,Kumar, Vishal,Singh, Bikram
supporting information; experimental part, p. 2289 - 2293 (2012/09/10)
Zinc phthalocyanine with PEG-400 was established as a catalytic system for chemo and regioselective reduction of aromatic nitro compounds to corresponding amines. A large range of reducible functional groups such as acid, amide, ester, halogen, lactone, nitrile, N-benzyl, O-benzyl, hydroxy and heterocycles were well tolerated. Direct synthesis of benzotriazole from O-dinitrobenzene was achieved for the first time. The present catalytic system was successfully employed for the reduction of carbonyl and ester compounds to corresponding alcohols and reductive amination of benzaldehydes with primary amines to form corresponding secondary amines. Remarkable advantages of the present catalytic method include low loading of metal, avoidance of toxic ligands and high isolated yields. The catalyst was recyclable up to four times without any loss of selectivity and activity.
Lithium amidoborane, a highly chemoselective reagent for the reduction of α,β-unsaturated ketones to allylic alcohols
Xu, Weiliang,Zhou, Yonggui,Wang, Ruimin,Wu, Guotao,Chen, Ping
experimental part, p. 367 - 371 (2012/01/13)
Lithium amidoborane (LiNH2BH3, LiAB for short), is capable of chemoselectively reducing α,β-unsaturated ketones to the corresponding allylic alcohols at ambient temperature. A mechanistic study shows that the reduction is via a double hydrogen transfer process. The protic H(N) and hydridic H(B) in amidoborane add to the O and C sites of the carbonyl group, respectively.
Efficient chemoselective biohydrogenation of 1,3-diaryl-2-propen-1-ones catalyzed by Saccharomyces cerevisiae yeasts in biphasic system
Silva, Vanessa Dutra,Stambuk, Boris Ugarte,Nascimento, Maria da Graca
experimental part, p. 157 - 163 (2010/10/19)
A series of chalcones (1-9) was synthesized by base catalyzed aldol condensation with 50-94% yields. These α,β-unsaturated carbonyl compounds were used as substrates in biotransformation reactions mediated by three industrial Saccharomyces cerevisiae strains in biphasic systems. Several reaction parameters were evaluated, such as yeast concentration, temperature, pH, substrate concentration, organic solvent, volume of aqueous and organic phases and the influence of substituent groups on chalcones 1-9. The biotransformation was chemoselective and formed only the corresponding saturated ketones. The highest conversion (>99%) to the dihydrochalcone was obtained at 30-45°C and pH above 5.5, while the cellular and substrate concentrations also showed a strong influence on the biohydrogenation reaction. Organic solvents with log. P >3.2 (hexane or heptane) were the most appropriate, and 40-80% of aqueous phase allowed the highest conversions probably by maintaining the yeast enzymes catalytically active. The influence of substituents on rings A and B of chalcones 1-9 was low and no correlation between the donor or withdrawing electron groups was observed.
Selective Reduction of the Carbonyl Group of Functional Nitroaromatic Derivatives: A New Application of Complex Reducing Agents ZnCRASi
Feghouli, Ghania,Vanderesse, Regis,Fort, Yves,Caubere, Paul
, p. 849 - 854 (2007/10/02)
The selective reduction of carbonyl group of aromatic nitroketones or aldehydes into aromatic nitroalcohols has been achived by Me3SiCl modified Zinc containing Complex Reducing Agent (ZnCRASi).
ALLYLIC ALCOHOLS VIA THE CHEMOSELECTIVE REDUCTION OF ENONE SYSTEMS WITH SODIUM BOROHYDRIDE IN METHANOLIC TETRAHYDROFURAN.
Varma, Rajender S.,Kabalka, George W.
, p. 985 - 990 (2007/10/02)
The selective reducing characteristics of sodium borohydride in a mixed tetrahydrofuran-methanol solvent system toward α,β-unsaturated ketones were investigated; allylic alcohols are procuced in good yield under mild conditions.
