Palladium-assisted formation of carbon-carbon bonds. 9. Synthesis of (2-alkenylaryl)- and indenylpalladium complexes

(o-Formylaryl)palladium complexes. [Pd{C6H(CHO)-6-R-3-2,3,4)X(N-N)] [R = OM e; X = Cl; N-N = bpy (2,2'-bipyridine) (la), tmeda (N,N,N',N'-tetramethylet hylenediamine) (Ib). R = H; X = Br; N-N = bpy (2a), tmeda (2b)] react with ylides PhCH=PPh3, pyCH=PPh3 (PY = 2-pyridyl), or ClCH=PPh3 to give the (o-a lkenylaryl)palladium derivatives [Pd{C6HCH=CHPh-6-(OMe)(3)-2,3,4)Cl(N-N)] [ N-N = bpy (3a), N-N = tmeda (3b)], [Pd{C6HCH= CHpy-6-(OMe)(3)-2,3,4}Cl(N-N) ] [N-N = bpy (4)], [Pd{C6H(E-CH=CHCl)-6-(OMe)(3)-2,3,4}-Cl(tmeda)] (5), or [Pd(C6H4CH=CHPh-2)Br(N-N)] [N-N = bpy (6a), N-N = tmeda (6b)], The compound s 3a, 4, and 6a,b are obtained as mixtures off and Z isomers, whereas the f ormation of 3b and 5 is stereoselective (E isomer). The reaction of the (o- acetylaryl)palladium complexes [Pd{C6HC(O)Me-6-(OMe)(3)-2,3,4}Cl(tmeda)] (7 ) and [Pd{C6H4(C(O)Me)-2}Br(bpy)] (8) with bases results in the formation o f the 3-palladaindan-1-ones [Pd(kappa (2)-{C6HC(O)CH2-6-(OMe)(3)-2,3,4})(tm eda)] (9) and [Pd(kappa (2)-{C6H4C(O)CH2-2)(bpy)] (10). Complexes 3b and 6a ,b react with alkynes-RC=CR' to give indenylpalladium complexes [Pd{eta -C9 HBn-1-R-2-R'-3-(OMe)(3)-5,6,7}(tmeda)]TfO [Bn = benzyl, TfO = CF3SO3, R = R ' = Me(11); R = C(O)Me, R' = H (12)] and [Pd{eta -C9H4Bn-1-R-2-R'-3}(N-N)]T fO [R = R' = H, N-N = bpy (13a), tmeda (13b); R = R' = Me, N-N = bpy (14a), tmeda (14b); R = R' = Et, N-N = bpy (15a), tmeda (15b); R = R' = Ph, N-N b py (16a), tmeda (16b); R = Ph, R' = H and R = H, R' = Ph, N-N = bpy (17a); R = H, R' = Ph, N-N = tmeda (17b); R = Ph, R' = Me, N-N = bpy (18a), N-N = tmeda (18b)]. Complex 3b reacts with Me2C=C=CH2, CS2, or MeN=C=S to give [P d(eta (3)-CMe2C{C6H(E-CH=CHPh)-6-(OMe)(3)-2,3,4}CH2)(tmeda)]TfO (19), [Pd(S 2C{C6H(E-CH=CHPh)-6-(OMe)(3)-2,3,4})(tmeda)]TfO (20), or [Pd(SC(NMe)(C6H(E- CH=CHPh)-6-(OMe)(3)-2,3,4})(tmeda)]TfO (21). The crystal structures of 12, 17b, and 18a have been determined; the hapticities of the indenyl five-memb ered rings are intermediate between eta (3) and eta (5).