1.1- carbonyl-bis

The first chiral phases introduced for gas chromatography were either amino acid esters, dipeptide, diamide or carbonyl-bis(amino acid ester) phases [721,724,756-758]. In general, these phases exhitdted poor thermal stability and are infrequently used today. Real interest and progress in chiral separations resulted from the preparation of diamide phases grafted onto a polysiloxane backbone. These phases were thermally stable and could be used to prepare efficient open tubular columns [734,756,758-762]. These phases are prepared from commercially available poly(cyano-propylmethyldimethylsiloxanes) or poly (cyanopropylmethylphenyl-... 

A variant of this method for the introduction of amino protecting groups into amino acids via the alkoxycarbonylimidazolium salts starts from the more reactive carbonyl-bis(methylimidazolium) salts [105]... 

Dipicryl-l,3,4-oxadiazole has been described as an initiating explosive, 2,5-dimethyl-l,3,4-oxadiazole has been used to extract aromatic hydrocarbons from mixtures with alkanes. The use of 4,4 -carbonyl-bis(2-phenyl-5-oxo-l,3,4-oxadiazole) as a blowing agent for foaming thermoplastic compositions (e.g., polycarbonates) has been described < 1996CHEC-II(4)268>. 

Bis(0-salieylidenaminopropylaziridine)iron(III) perchlorate, 3853 Bis(tetramethyldiphosphane disulfide)cadmium perchlorate, 3102 Carbonyl-bis(triphenylphosphine)iridium-silver diperchlorate, 3898 5-/ -Chlorophcnyl-2.2-dimcthy 1-3-hcxanonc. 3664 Copper(II) perchlorate, Polyfimctional amines, 4057 Copper(II) perchlorate, /V-(2-Pyridyl)acylacctamidcs. 4057 2(5-Cyanotetrazole)pentaamminecobalt(III) perchlorate, 0974 1,5-Cyclooctadiene-bis(4-chloropyridine /V-oxidc)rhodium(I) perchlorate, 3761... 

Several aromatic acyl silanes and the fascinating but unstable pink carbonyl bis(trimethylsilane) have been prepared in reasonably good yields by the oxidation of phosphonium ylids (Scheme 17)13. 

Remarkably, carbonyl bis(trimethylsilane) can act as a source of the CO2- dianion in the presence of fluoride ion (Scheme 82)13. 

Carbonyl-bis(triphenylphosphine)iridium—silver diperchlorate, 3892 Carbonyl dicyanide, see Oxopropanedinitrile, 1337 Carbonyl difluoride, 0342a Carbonyl diisothiocyanate, 1338 Carbonyl(pentasulfur pentanitrido)molybdenum, 0532 2-Carboxy-3,6-dimethylbenzenediazonium chloride, 3132a Carboxymethyl carbamimoniothioate chloride,... 

There have been many reported chiral stationary phases for use in both packed and capillary gas chromatography. Most of these phases are of the carbonyl-bis-L-valine isopropyl ester, diamide, and peptide phase types. The most common phase is Chirasil-Val from Alltech Applied Science Laboratories (State College, PA). This phase is ideal for the separation of a variety of enantiomers including amino acids, sugars, amines, and peptides. The phase is composed of L-valine-tert-butylamide linked through a car-oxamide group to a polysiloxane backbone every seven dimethylsiloxane units apart. 

Kranemann CL, Eilbracht P (1998) One-pot synthesis of tertiary a,catalyst precursor. Synthesis 1998(01) 71—77, 10.1055/s-1998-4481... 

Indene (0.10 mole) was dissolved in 60 ml THF, 200 ml 1.0 M lithium bistrimethylsilylamide (0.20 mole) in THF added over 1 hour, and stirred for 30 minutes. Thereafter, N-t-butoxy-carbonyl-bis(2-chloroethyl)amine (0.10 mole) dissolved in 50 ml THF was added, the mixture further stirred 2 hours, and then distilled under reduced pressure. The residue was purified by chromatography on silica gel using n-hexane/EtOAc, 97 3, and the product isolated in 89% yield. H-NMR, IR, and MS data supplied. 

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