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Metallaboranes from Metal Carbonyl Compounds and Their Utilization as Catalysts for Alkyne Cyclotrimerization.
- Source :
-
ChemPlusChem . Apr2014, Vol. 79 Issue 4, p546-551. 6p. - Publication Year :
- 2014
-
Abstract
- The photolysis of [M2(CO)10] (M=Re or Mn) with BH3⋅thf at room temperature yields arachno -1 and 2, [(CO)8M2B2H6] ( 1: M =Re, 2: M =Mn). Both the compounds show a butterfly structure with seven skeletal electron pairs and 42 valence electrons. This result presents a new method for general access to low-boron-content metal-boron compounds without the cyclopentadienyl ligand at the metal centers. This new synthetic route is superior to the existing procedures because it avoids the use of [LiBH4] and metal polychlorides, for which the synthesis is very tedious. Compound 1 catalyzes the cyclotrimerization of a series of internal and terminal alkynes to yield mixtures of 1,3,5- and 1,2,4-substituted benzenes. The reactivity of 1 with alkynes demonstrates for the first time that the introduction of the [B2H6] moiety into the [Re2(CO)10] framework significantly enhances the catalytic activity. Note that [Re2(CO)10] catalyzes the same set of alkynes under harsh conditions over a prolonged period of time. Quantum-chemical calculations using DFT methods are applied to afford further insight into the electronic structure, stability, and bonding of 1 and 2. All the compounds are characterized by IR and 1H, 11B, and 13C NMR spectroscopy, and the geometry of 1 is established unambiguously through crystallographic analysis. [ABSTRACT FROM AUTHOR]
- Subjects :
- *METAL carbonyls
*CATALYSTS
*ALKYNES
*PHOTOLYSIS (Chemistry)
*ELECTRONS
Subjects
Details
- Language :
- English
- ISSN :
- 21926506
- Volume :
- 79
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- ChemPlusChem
- Publication Type :
- Academic Journal
- Accession number :
- 95562510
- Full Text :
- https://doi.org/10.1002/cplu.201400013