Tungsten isomerism with substituted

Schmidt reaction of ketones, 7, 530 from thienylnitrenes, 4, 820 tautomers, 7, 492 thermal reactions, 7, 503 transition metal complexes reactivity, 7, 28 tungsten complexes, 7, 523 UV spectra, 7, 501 X-ray analysis, 7, 494 1 H-Azepines conformation, 7, 492 cycloaddition reactions, 7, 520, 522 dimerization, 7, 508 H NMR, 7, 495 isomerization, 7, 519 metal complexes, 7, 512 photoaddition reactions with oxygen, 7, 523 protonation, 7, 509 ring contractions, 7, 506 sigmatropic rearrangements, 7, 506 stability, 7, 492 N-substituted mass spectra, 7, 501 rearrangements, 7, 504 synthesis, 7, 536-537... 

Cationic polymerization of substituted alkyl-1,3-butadienes is accompanied by a considerable loss of double bonds (up to 80%) due to the formation of cyclic products [346]. Tin(IV) chloride in trichloracetic acid, tungsten(VI) chloride, and boron trifluoride etherate have been tested as cationic catalysts [347, 348]. In addition to polymerization, isomerizations are observed with these catalysts. 

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