摘要:

Hydrolytic Stable Ammonium Salts of Sulfonated Organic Phosphites and their Use as Cocatalysts in the Rhodium‐catalyzed Hydroformylation of OlefinsAmmonium salts of sulfonated organic phosphites, which are resistant to hydrolysis, have been prepared by transesterification of triphenylphosphite with mono‐ammonium salt of p‐hydroxyphenylsulfonic acid in yields between 66 and 76%. A mixture containing triisooctylammonium salts of sulfonated triphenylphosphite [TPPp‐SO3HN(i‐octyl)3] was submitted to a test for stability to hydrolysis. The time required for hydrolysis of 7.4% of the TPPp‐SO3HN(i‐octyl)3was 3 hours under drastic conditions. Triphenylphosphite was in the same test hydrolyzed quantitatively within three hours.Tetradec‐1‐ene was hydroformylated by means of the catalytic systems consisting of rhodium‐2‐ethylhexanoate with either TPPp‐SO3HN(i‐octyl)3, triphenylphosphite (TPPp) or triphenylphosphine (TPP) at 125°C, 0.6 MPa and a rhodium concentration of 50 ppm. Higher reaction selectivities for linear aldehydes were achieved with the rhodium/TPPp‐SO3HN(i‐octyl)3catalytic system. Reaction rates increased with the Rh/TPPp‐SO3HN(i‐octyl)3catalyst at lower temperature (110°C). Using this catalyst at 110°C, higher yields are achieved than with the Rh/TPP or Rh/TPPp catalysts.Hex‐1‐ene was hydroformylated by using the catalytic systems Rh4(CO)12with TPPp‐SO3HN(i‐octyl)3, Rh4(CO)12TPP or Rh4(CO)12with TPPp at 125°C, 2,5 MPa and a rhodium concentration of 20 ppm. This confirms the above experiments which indicated that higher linear: branched aldehyde ratios were obtained

ISSN:0941-1216    

DOI:10.1002/prac.19933350112

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

AbstractThe primary structure of a pyoverdin (Pa TII) isolated from an iron deficient culture medium ofPseudomonas aeruginosaATCC 27 853 has been elucidated by spectroscopic methods and degradation studies. Total assignment of1H and13C resonances as well as sequential information were achieved by two‐dimensional NMR techniques: HOHAHA1, NOESY, HSQC and HMBC. The structure consists of the common pyoverdin chromophore 5‐amino‐2,3‐dihydro‐8,9‐dihydroxy‐1H‐pyrimido [1,2‐a]quinoline‐1‐carboxylic acid with succinic acid bound amidically to its amino group and the carboxyl group linked to the N‐terminus of D‐Ser‐D(CHO) OHOrn‐L‐Orn‐Gly‐D‐aThr‐L‐Ser‐L‐cOHOrn. According to the short‐hand nomenclature suggested in [2, 3]the pyoverdin m

ISSN:0941-1216    

DOI:10.1002/prac.19933350113

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

摘要:

Synthesis of PyrazolyldithiocarbonatesThe reaction of 3‐amino‐pyrazole1with carbondisulfide and alkylating agents in basic conditions to yield different dithiocarbonates2–8was studied. The dithiocarbonates2areact with isocyanates to form 1‐acyl‐5‐acylamino‐pyrazoles9–10. Acyl migrations were observed depending on the reaction temperature and the isocyanates.The results obtained enable us to correct some confusions in the literature about thioure

ISSN:0941-1216    

DOI:10.1002/prac.19933350114

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350115

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350116

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350117

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350118

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350119

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350120

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY

ISSN:0941-1216    

DOI:10.1002/prac.19933350101

出版商:WILEY‐VCH Verlag GmbH    

年代:1993

数据来源: WILEY