Synthesis of <i>meta</i>
-Functionalized Pyridines by Selective Dehydrogenative Heterocondensation of β- and γ-Amino Alcohols
作者:Toni Hille、Torsten Irrgang、Rhett Kempe
DOI:10.1002/anie.201610071
日期:2017.1.2
concepts to synthesize meta‐functionalized pyridines. First, diols and amines were linked to β‐aminoalcohols, which can then undergo a selective dehydrogenative heterocondensation with γ‐aminoalcohols. Iridium catalysts stabilized by PN5P pincer ligands that were developed in our laboratory mediate the reactions most efficiently. All of the 3‐aminopyridines that we describe in this paper have been synthesized
N-Fluorobenzenaminium tetrafluoroborate generated in situ by aniline and Selectfluor as a reusable catalyst for the ring opening of epoxides with amines under microwave irradiation
The ringopening of epoxides with aromatic and aliphatic amines was carried out under solvent free conditions using N-fluorobenzenaminium tetrafluoroborate (2 mol%) generated in situ by the reaction of aniline and Selectfluor as a catalyst with microwave irradiation. Excellent yields of β-amino alcohols were obtained. The catalyst also results in the retention of the stereochemistry for the ring opening
Conversion of Carbon Dioxide into Oxazolidinones Mediated by Quaternary Ammonium Salts and DBU
作者:Min Lv、Peng Wang、Dan Yuan、Yingming Yao
DOI:10.1002/cctc.201700594
日期:2017.12.20
A straightforward method to construct oxazolidinones through a three‐component reaction involving CO2, epoxides, and amines promoted by a combination of Bu4NI and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene was developed. A wide range of aromatic and aliphatic amines and monosubstituted epoxides were converted into 3,5‐disubstituted‐2‐oxazolidines in up to 95 % yield. This metal‐free and easily available catalytic
Synthesis of 1,2-amino alcohols by decarboxylative coupling of amino acid derived α-amino radicals to carbonyl compounds <i>via</i> visible-light photocatalyst in water
coupling reaction of N-aryl amino acids with aldehydes or ketones for the synthesis of various 1,2-amino alcohols by using water as the solvent at room temperature is described. This protocol is characterised by broad substrate scopes, mild reaction conditions and amenability to gram-scale synthesis, which opens up a simple, mild but effective method to produce 1,2-amino alcohols from readily available
A solvent-free approach for the regioselective synthesis of β-amino alcohols inshorter reaction times and higher yields, compared to conventional heating is described. Itinvolves microwave (MW) exposure of undiluted reactants in the presence of sulphatedzirconia (SZ) or sulphated zirconia over MCM-41 (SZM) as catalyst. Both acid materialscan be easily recovered and reused.