An efficient and simple synthesis of a-hydroxyphosphonates via reaction of aldehydes and ketones with di- methylphosphite in the presence of MgCI2/Et3N base system is reported. The use of readily available and easy to...An efficient and simple synthesis of a-hydroxyphosphonates via reaction of aldehydes and ketones with di- methylphosphite in the presence of MgCI2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCI2/Et3N makes this method simple, convenient, and practical.展开更多
1-Phenyl-2-acetoxy-2-methyl-propanone, a new a-hydroxy ketone derivative, was synthesized by Friedel-Crafts acylation and characterized by FT-IR, 1H NMR, MS spectra and single-crystal X-ray diffraction measurements. T...1-Phenyl-2-acetoxy-2-methyl-propanone, a new a-hydroxy ketone derivative, was synthesized by Friedel-Crafts acylation and characterized by FT-IR, 1H NMR, MS spectra and single-crystal X-ray diffraction measurements. The data are as follows： monoclinic, space group P21/c, Z = 4, C12H1403, Mr = 206.24, a = 8.9430（2）, b =15.2680（4）, c = 8.2550（2） A, β = 91.9650（5）°, V = 1126.60（5）A^3, Dc = 1.216 g/cm^3, μ（MoKα） = 0.087 mm^-1, F（000） = 440, R = 0.0725 and wR = 0.1379 for 1282 observed reflections with I〉 2σ（I）. The structure was solved by direct methods and refined by full-matrix least-squares refinement on F2 methods. The benzene ring in the structure is almost coplanar with the adjacent carbonyl groups and t-carbonyl atom. Meanwhile, the long chain is approximately perpendicular to the plane. X-ray analysis reveals that the crystal structure involves two weak intramolecular C-H…O hydrogen bonds.展开更多
Enantiopure vicinal diols are important building blocks used in the synthesis of fine chemicals and pharmaceutical compounds. Diol dehydrogenase(DDH) mediated stereoselective oxidation of racemic vicinal is an efficie...Enantiopure vicinal diols are important building blocks used in the synthesis of fine chemicals and pharmaceutical compounds. Diol dehydrogenase(DDH) mediated stereoselective oxidation of racemic vicinal is an efficient way to prepare enantiopure vicinal diols. In this study, four new bacterial DDHs(AnDDH from Anoxybacillus sp. P3 H1 B, HcDDH from Hazenella coriacea, GzDDH from Geobacillus zalihae and LwDDH from Leptotrichia wadei) were mined from the GenBank database and expressed in E. coli T7.The four DDHs were purified and biochemically characterized for oxidation activity toward(R)-1-phenyl-1,2-ethanediol, with the optimal reaction condition of pH9.0(AnDDH), 10.0(HcDDH) and 11.0(GzDDH and LwDDH) and the temperatures at 40 ℃(AnDDH), 50 ℃(HcDDH) and 60 ℃(GzDDH and LwDDH), respectively. The four enzymes were stable at the pH from 7.0 to 9.0 and below 40 ℃.Kinetic parameters of four DDHs showed that the HcDDH from Hazenella coriacea had high activity toward a broad range of vicinal diols. A series of racemic vicinal diols were successfully resolved by recombinant E. coli(HcDDH-NOX) resting cells co-expression of an NADH oxidase(NOX), affording(S)-diols and(1 S, 2 S)-trans-diols in ≥99% ee. The synthetic potential of HcDDH was proved by E. coli(HcDDH-NOX) via kinetic resolution of racemic trans-1,2-indandiol on a 100 ml scale reaction,(S, S)-trans-1,2-indandiol was prepared in 46.7% yield and >99% ee. In addition, asymmetric reduction of four α-Hydroxy ketones(10–300 mmol·L^(-1)) by E. coli(HcDDH-GDH) resting cells resulted in >99% ee and69–98% yields of(R)-vicinal diols. The current research expands the toolbox of DDHs to synthesize chiral vicinal diols and demonstrated that the mined Hc DDH is a potential enzyme in the synthesis of a broad range of chiral vicinal diols.展开更多
Various aromatic α-keto esters were rapidly and selectively reduced to aromatic α-hydroxy esters by commercially available zinc dust and ammonium formate in the presence of other functional groups such as halogens, ...Various aromatic α-keto esters were rapidly and selectively reduced to aromatic α-hydroxy esters by commercially available zinc dust and ammonium formate in the presence of other functional groups such as halogens, methoxy and esters.展开更多
An efficient phospho-aldol reaction of aldehydes catalyzed by N-heterocyclic carbenes （NHCs） has been developed. With 10 mol% stable NHC 1,3-bis（2,6-diisopropylphenyl）imidazol-2-ylidene, various aldehydes reacted ...An efficient phospho-aldol reaction of aldehydes catalyzed by N-heterocyclic carbenes （NHCs） has been developed. With 10 mol% stable NHC 1,3-bis（2,6-diisopropylphenyl）imidazol-2-ylidene, various aldehydes reacted with dialkylphosphites smoothly to provide a-hydroxy phosphonates in 59%--99% yield. In this process, NHC was assumed to function as a carbon-centered bronsted base.展开更多
文摘An efficient and simple synthesis of a-hydroxyphosphonates via reaction of aldehydes and ketones with di- methylphosphite in the presence of MgCI2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCI2/Et3N makes this method simple, convenient, and practical.
基金Supported by the Scientific and Technical Personnel Service Enterprise Foundation of State Ministry of Science and Technology (2009GJD10016)The Major Production-Study-Research Foundation of Education Department of Hubei Province (CXY2009A010)the Natural Science Foundation of Hubei Province (2010CDA020)
文摘1-Phenyl-2-acetoxy-2-methyl-propanone, a new a-hydroxy ketone derivative, was synthesized by Friedel-Crafts acylation and characterized by FT-IR, 1H NMR, MS spectra and single-crystal X-ray diffraction measurements. The data are as follows： monoclinic, space group P21/c, Z = 4, C12H1403, Mr = 206.24, a = 8.9430（2）, b =15.2680（4）, c = 8.2550（2） A, β = 91.9650（5）°, V = 1126.60（5）A^3, Dc = 1.216 g/cm^3, μ（MoKα） = 0.087 mm^-1, F（000） = 440, R = 0.0725 and wR = 0.1379 for 1282 observed reflections with I〉 2σ（I）. The structure was solved by direct methods and refined by full-matrix least-squares refinement on F2 methods. The benzene ring in the structure is almost coplanar with the adjacent carbonyl groups and t-carbonyl atom. Meanwhile, the long chain is approximately perpendicular to the plane. X-ray analysis reveals that the crystal structure involves two weak intramolecular C-H…O hydrogen bonds.
基金supported by the National Natural Science Foundation of China(Grant No.21772141)the Shanxi Province Science Foundation for Youths(grant No.201701D221042)the Key Research and Development(R&D)Project of Shanxi Province(201803D31050).
文摘Enantiopure vicinal diols are important building blocks used in the synthesis of fine chemicals and pharmaceutical compounds. Diol dehydrogenase(DDH) mediated stereoselective oxidation of racemic vicinal is an efficient way to prepare enantiopure vicinal diols. In this study, four new bacterial DDHs(AnDDH from Anoxybacillus sp. P3 H1 B, HcDDH from Hazenella coriacea, GzDDH from Geobacillus zalihae and LwDDH from Leptotrichia wadei) were mined from the GenBank database and expressed in E. coli T7.The four DDHs were purified and biochemically characterized for oxidation activity toward(R)-1-phenyl-1,2-ethanediol, with the optimal reaction condition of pH9.0(AnDDH), 10.0(HcDDH) and 11.0(GzDDH and LwDDH) and the temperatures at 40 ℃(AnDDH), 50 ℃(HcDDH) and 60 ℃(GzDDH and LwDDH), respectively. The four enzymes were stable at the pH from 7.0 to 9.0 and below 40 ℃.Kinetic parameters of four DDHs showed that the HcDDH from Hazenella coriacea had high activity toward a broad range of vicinal diols. A series of racemic vicinal diols were successfully resolved by recombinant E. coli(HcDDH-NOX) resting cells co-expression of an NADH oxidase(NOX), affording(S)-diols and(1 S, 2 S)-trans-diols in ≥99% ee. The synthetic potential of HcDDH was proved by E. coli(HcDDH-NOX) via kinetic resolution of racemic trans-1,2-indandiol on a 100 ml scale reaction,(S, S)-trans-1,2-indandiol was prepared in 46.7% yield and >99% ee. In addition, asymmetric reduction of four α-Hydroxy ketones(10–300 mmol·L^(-1)) by E. coli(HcDDH-GDH) resting cells resulted in >99% ee and69–98% yields of(R)-vicinal diols. The current research expands the toolbox of DDHs to synthesize chiral vicinal diols and demonstrated that the mined Hc DDH is a potential enzyme in the synthesis of a broad range of chiral vicinal diols.
文摘Various aromatic α-keto esters were rapidly and selectively reduced to aromatic α-hydroxy esters by commercially available zinc dust and ammonium formate in the presence of other functional groups such as halogens, methoxy and esters.
基金the National Natural Science Foundation of China，the Team Innovation Project of Shihezi University
文摘An efficient phospho-aldol reaction of aldehydes catalyzed by N-heterocyclic carbenes （NHCs） has been developed. With 10 mol% stable NHC 1,3-bis（2,6-diisopropylphenyl）imidazol-2-ylidene, various aldehydes reacted with dialkylphosphites smoothly to provide a-hydroxy phosphonates in 59%--99% yield. In this process, NHC was assumed to function as a carbon-centered bronsted base.
