ISSN:
0009-2940
Keywords:
Titanocene complexes
;
Zirconocene complexes
;
Metallabicyclo[3.1.0]hexenes
;
4-Vinyl-1-metallacyclobutenes
;
Oxidative coupling of alkynes with cyclopropenes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Metallabicyclo[3.1.0]hexenes and Their Rearrangement to Vinylmetallacyclobutenes (M=Ti, Zr)Alkyne-metallocene complexes, e.g. the alkynetitanocenes 1a, b, the alkyne(trimethylphosphane)titanocenes 2a, b and the alkyne(trimethylphosphane)zirconocenes 5a-d react readily with 3,3-dimethylcyclopropene (3a) and 3,3-diphenylcyclopropene (3b) to give the corresponding bis(η5-cyclopentadienyl)-metallabicyclo[3.1.0]hexene derivatives 4a-e, (M=Ti) and 6a-g (M=Zr) in high yields. In an analogous manner, metallabicyclo[3.1.0]hexene derivatives of Ti or Zr can be prepared from 1,2-diphenylcyclopropene(trimethylphosphane)metallocenes 9 and 10 and 2-butyne to yield 11 and 12 and from benzyne 3a or 3b to yield 8a and 8b. Some of these metallabicyclo[3.1.0]hexene derivatives rearrange quantitatively to the corresponding 4-(dimethylvinyl)-1-metalla-2-cyclobutene derivates 16 and 17a and 4-(diphenylvinyl)-1-metalla-2-cyclobutenes 15c and 17a-c when they are heated to 60-80°C for several hours. The 4-(diphenylvinyl)-1-titana-2-cyclobutene derivatives 15a-c can also be obtained by reaction of [(2,2-diphenylvinyl)carbene](trimethylphosphane)-titanocen (13) with disubstituted alkynes such as tolane, phenyltrimethylsilylacetylene and bis(trimethylsily)acetylene. With other alkynes, e.g. 2-butyne, 1-butyne, 1-propyne or acetylene, 13 reacts by polymerization of these alkynes; the corresponding 4-vinyl-1-titanacyclobutene derivatives could not be detected in the reaction mixture. All new metallacycles are fully characterized by spectroscopic methods, extensive 1H- and 13C-NMR studies provide unambiguous proof of their structures.
Additional Material:
6 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931260707
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