Diastereo- and enantioselective dearomatization of rhenium-bound naphthalenes.
Dihapto-coordinated naphthalene complexes of the form TpRe(CO)(L)(eta(2)-naphthalene) (L = PMe(3), pyridine, or 1-methylimidazole) undergo electrophilic addition with dimethoxymethane and with various Michael acceptors to generate 1H-naphthalenium species. These naphthalenium complexes undergo intra- or intermolecular nucleophilic addition reactions with stabilized enolates, silyl ketene acetals, or enols to form the corresponding dihydronaphthalene complexes. Oxidative decomplexation generates the free dihydronaphthalene. When a resolved form of the rhenium dearomatization agent is used, these reactions can be performed enantioselectively. DFT calculations provide a useful guide in explaining the observed stereochemistry. Depending on reaction conditions, a Michael-Michael ring-closure sequence (MIMIRC) or a net [2 + 4] cycloaddition with the bound naphthalene is also observed, and the corresponding tricyclic molecules can be removed from the metal in high yield.
Ding
Fei
F
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA.
Valahovic
Mark T
MT
Keane
Joseph M
JM
Anstey
Mitchell R
MR
Sabat
Michal
M
Trindle
Carl O
CO
Harman
W Dean
WD
D002384:Catalysis; D007202:Indicators and Reagents; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D012211:Rhenium / Q000737:chemistry*; D013237:Stereoisomerism
D007202:Indicators and Reagents; D009281:Naphthalenes; D009942:Organometallic Compounds; D012211:Rhenium