Synthesis of Coordinated η2-α,β-Unsaturated Ketone Osmacycles from an Osmium-Coordinated Alkyne Alcohol Complex
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- 作者：Lei Gong ; Yumei Lin ; Ting Bin Wen* ; Haiping Xia*
- 刊名：Organometallics
- 出版年：2009
- 出版时间：February 23, 2009
- 年：2009
- 卷：28
- 期：4
- 页码：1101-1111
- 全文大小：377K
- 年卷期：v.28,no.4(February 23, 2009)
- ISSN：1520-6041
文摘
The study on the reactivity of an osmium-coordinated alkyne alcohol complex OsCl2(CHC(PPh3)CH(OH)-η2-CCH)(PPh3)2 (1) has been carried out. Treatment of 1 with acetic acid, ethylene diamine, 2,2′-bipyridine, trimethylphospine, or tributylphosphine led to the formation of several coordinated η2-α,β-unsaturated ketone osmacycles, including OsCl2(CHC(PPh3)C(O)-η2-CHCH2)(PPh3)2 (3), [OsCl(CHC(PPh3)C(O)-η2-CHCH2)(PPh3)(H2NCH2CH2NH2)]Cl (4), [OsCl(CHC(PPh3)C(O)-η2-CHCH2)(PPh3)(2,2′-bipy)]Cl (5), OsCl2(CHC(PPh3)C(O)-η2-CHCH2)(PMe3)2 (6), [OsCl(CHC(PPh3)C(O)-η2-CHCH2)(PMe3)3]Cl (8), and OsCl2(CHC(PPh3)C(O)-η2-CHCH2)(PBu3)2 (9). Similar chemistry was also observed starting from OsBr2(CHC(PPh3)CH(OH)-η2-CCH)(PPh3)2 (10), which afforded OsBr2(CHC(PPh3)C(O)-η2-CHCH2)(PPh3)2 (11) on treatment with acetic acid. All these cyclic α,β-unsaturated ketone complexes are air-stable in the solid state, and most of them are also stable in solution except for OsCl2(CHC(PPh3)C(O)-η2-CHCH2)(PMe3)2 (6) and [OsCl(CHC(PPh3)C(O)-η2-CHCH2)(PMe3)3]Cl (8). Complex 8 can isomerize to the osmaphenol [OsCl(CHC(PPh3)C(OH)CHCH)(PMe3)3]Cl (12) as the major product in dry chloroform, but transforms into the osmafuran [Os(CO)(CHC(PPh3)C(CH3)O)(PMe3)3]Cl2 (13) in wet chloroform, while complex 6 is stable in dry solvent, but can convert to the osmafuran [OsCl(CO)(CHC(PPh3)C(CH3)O)(PMe3)2]Cl (14). The remarkable thermostability and chemical stability of the coordinated α,β-unsaturated ketone osmacycles have been studied preliminarily with 3 as a representative example. The coordinated α,β-unsaturated ketone metallacyclic framework of 3 is stable in different ligand environments. For example, treatment of 3 with carbon monoxide led only to ligand substitution to produce OsCl2(CHC(PPh3)C(O)-η2-CHCH2)(CO)(PPh3) (15).