Abstract
Reactions of [H2Os3(CO)10] with the substituted diynes R-C2-C2-R′ (1, R = Ph, R′ = CH2NHPh; 2, R = Ph, R′ = CH2NHCH2Ph; 3, R = R′ = CH2NHPh) afford the clusters [HOs3(CO)10(L)] (L = {μ-η1:η2-PhCH2C(H)=C-C(H)=C-NPh} (4), {μ-η1:η2-PhCH2C(H)=C-C(H)= C-NCH2Ph} (5), and {μ-η1:η1-CH3CC=C-C(H)=C(H)-NPh} (6), which have been characterized by single-crystal X-ray diffraction analyses as well as by various spectroscopic methods. In clusters 4-6, the starting diynes 1-3 have been rearranged to form substituted pyrrolyl rings which bridge two osmium atoms in η1:η2- (4, 5) or η1:η1- (6) coordination modes depending on the nature of substituents in 1-3. A possible reaction pathway for the diyne cyclization reactions that yield 4-6 involves initial transfer of a hydride onto a coordinated diyne followed by a series of 1,3-shifts and subsequent nucleophilic attack of the nitrogen on the third carbon atom of the diyne system to afford the five-membered pyrrolyl ring. Cluster 6 and its previously characterized furanyl analogue [HOs3(CO)10{μ-η1:η1-(OCH- CHCC)-C-CH3)}] (7) undergo facile thermal transformation accompanied by the loss of a CO ligand to give the clusters [HOs3(CO)9{μ3,η3- CH3CC=C-C(H)=C(H)-NPh}] (8) and [HOs3(CO)9{μ3,η3-(OCH=CHC= CCCH3)}] (9). In both 8 and 9, single-crystal X-ray analysis revealed the presence of pentagonal pyramid cluster cores containing three osmium and three carbon atoms.
Original language | English |
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Pages (from-to) | 3854-3863 |
Number of pages | 10 |
Journal | Organometallics |
Volume | 20 |
Issue number | 18 |
DOIs | |
Publication status | Published - 3 Sept 2001 |
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry