Insertion of alkynes with electron-withdrawing substituents into a rhenium-rhenium bond. Evidence for an intramolecular insertion with a trans stereochemistry
- Univ. of South Carolina, Columbia, SC (United States)
The reaction of the dirhenium complex re{sub 2}-(CO){sub 9}(NCMe) (1) with electrophilic alkynes, R`C{Nu}CCO{sub 2}R, proceeds by displacement of the NCMe ligand and addition of the alkyne with insertion into the rhenium-rhenium bond to yield the dimetalated olefin complexes Re(CO){sub 4-} [trans-{mu}-R`C=C(CO{sub 2}R)]Re(CO){sub 5} (R = Me, R` = H (2a), Me (2b); R = Et, R` = CO{sub 2}Et (2c)) having a trans stereochemistry at the C-C double bond. The carbolxylate group is coordinated to one of the rhenium atoms to form a metallacycle. Insensitivity to radical scavengers and the absence of crossover in a reaction of a mixture of labeled and unlabeled reagants indicate that the insertion of the alkyne into the metal-metal bond occurs by an intramolecular process. Crystal data for 2a: space group P2{sub 1}/n, a = 6.644f (1) A, b = 30.005 (8)A, c = 18.036 (2) A, {Beta} = 96.09 (1){degrees}, Z = 8, 2468 reflections, R = 0.033. 14 refs., 1 fig.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 411997
- Journal Information:
- Organometallics, Journal Name: Organometallics Journal Issue: 11 Vol. 11; ISSN ORGND7; ISSN 0276-7333
- Country of Publication:
- United States
- Language:
- English
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