Pentafluorophenyl cyclopentadiene

Pentafluorophenyl-substituted cyclopentadienide anions are useful ligands for transition metals because tbe CgFs substituent is not only bigbly electron withdrawing but also relatively stable.Up to four CsFs substituents may be attached to cyclopentadiene (or up to two to indene ) by one-pot nucleophilic aromatic substitution reactions of cyclopentadienyl or indenyl anions with hexafluoroben-zene. The title diene was also reported as the major organic product of the photolysis of Cp2Ti(CgF5)2. ... 

Bis(triphenyltin)dihydridobis(methyldiphenylphosphine)plati-num, see Sn-00474 Bis(triphenyltin)oxide, see Sn-00440 >Bis(triphenyltin) sulfide, Sn-00443 Bis(triphenyltin)telluride, Sn-00446 >Bis(tripropyltin) oxide, see Sn-00339 >Bis[tris(2-methyl-2-phenylpropyl)tin] oxide, see Sn-00473 Bis[tris(pentafluorophenyl)germyl]cadmium, Ge-00271 Bis[tris(pentafluorophenyl)germyl] mercury, Ge-00273 Bis[tris(pentafluorophenyl)germyl] selenide, see Ge-00275 Bis[tris(pentafluorophenyl)germyl] sulfide, see Ge-00274 [Bis[tris(pentafluorophenyl)stannyl]]mercury, Sn-00435 Bis[tris(trifluoromethyl)germanium]oxide, see Ge-00064 Bis[tris[(trimethylsilyl)methyl]stannyl]mercury, Sn-00399 Bromo( 7 -2,4-cyclopentadien-1 -yl)lead, Pb-00035 Bromo( 7 -2,4-cyclopentadien-1 -yl)tin, Sn-00086 Bromodimethylstannane, Sn-00022... 

Recently, Yamamoto and coworkers observed a unique form of chemoselectivity in the Diels-Alder reaction of a,P-unsaturated aldehydes and a,P-unsaturated ketones with cyclohexadiene. Upon subjecting a 1 1 mixture of acrolein and ethyl vinyl ketone toward cycloaddition with one equivalent of cyclopentadiene, the bulky tris-pentafluorophenyl boron Lewis acid (C6F5)3B gives primarily the cycloadduct of the a,p-unsaturated aldehyde, and on the contrary, Tf2NH gives mainly the cycloaddition adduct of the a,p-unsaturated ketone (Equation 14) [20]. 

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