362058-93-3Relevant academic research and scientific papers
Iridacyclopentadiene reactions with terminal alkynes: Tandem cycloaromatization and orthometalation
O'Connor, Joseph M.,Closson, Adam,Hiibner, Kristin,Merwin, Richard,Gantzel, Peter,Roddick, Dean M.
, p. 3710 - 3717 (2008/10/08)
Treatment of the iridacyclopentadiene complex [{(CH3C(CH2PPh2)3}Ir(CR=CRCR=CR)-Cl] (1, R = CO2CH3) with silver tetrafluoroborate, followed by addition of a terminal alkyne (ethyne, ethyl ethnynyl ether, methyl propargyl ether), yields iridium(III) aryl-hydride complexes[{(CH3C(CH2PPh2)3} Ir{C=C(C=OOMe)C(CO2Me)=C(CO2Me)C(CO2Me)= C(R1)}H]-BF4 (6-H, R1 = H; 6-OEt, R1 = OCH2CH3; 6-CH2OMe, R1 = CH2OCH3). The structure of 6-OEt was established by X-ray crystallographic analysis. Treatment of 6-H with either HCl or carbon monoxide results in demetalation to give tetramethyl 1,2,3,4-benzenetetracarboxylate [C6(CO2Me)4H2]. When 3-butyn-2-ol and propargyl alcohol are employed as substrates, a similar reaction occurs with 1/AgBF4 to produce the phthalimidyl complexes [{(CH3C(CH2PPh2)3}Ir{C=C(C=OOMe) C(CO2Me)=C(CO2Me)C(C=O)=CCHR1O}H] BF4 (7-H, R1 = H; 7-Me, R1 = CH3). The lactone ring in 7 is generated from an intramolecular transesterification of the hydroxyl with an adjacent methyl ester. In all cases these products are attributed to tandem cycloaromatization and orthometalation processes.
