Palladium-Assisted Formation of Carbon−Carbon Bonds. 9. Synthesis of (2-Alkenylaryl)- and Indenylpalladium Complexes

Abstract

o-Formylaryl)palladium complexes [Pd{C 6 H(CHO)-6-R 3 -2,3,4}X(N-N)] [R ) OMe; X ) Cl; N-N ) bpy (2,2′-bipyridine) (1a), tmeda (N,N,N′,N′-tetramethylethylenediamine) (1b). R ) H; X ) Br; N-N ) bpy (2a), tmeda (2b)] react with ylides PhCHdPPh 3 , pyCHdPPh 3 (py ) 2-pyridyl), or ClCHdPPh 3 to give the (o-alkenylaryl)palladium derivatives [Pd{C 6 -The compounds 3a, 4, and 6a,b are obtained as mixtures of E and Z isomers, whereas the formation of 3b and 5 is stereoselective (E isomer). The reaction of the (o-acetylaryl)palladium complexes [Pd{C 6 HC(O)Me-6-(OMe) 3 -2,3,4}Cl(tmeda)] ( 7) and [Pd{C 6 H 4 (C(O)Me)-2}Br(bpy)] (8) with bases results in the formation of the 3-palladaindan-1-ones [Pd(κ 2 -{C 6 HC(O)CH 2 -6-(OMe) 3 -2,3,4})(tmeda)] (9) and [Pd(κ 2 -{C 6 H 4 C(O)CH 2 -2}(bpy)] (10). Complexes 3b and 6a,b react with alkynes RCtCR′ to give indenylpalladium complexes [Pd{η-C 9 HBn-1-R-2-R′-3-(OMe) 3 -5,6,7}(tmeda)]TfO [Bn ) benzyl, TfO ) CF 3 SO 3 , R ) R′ ) Me (11); R ) C(O)Me, R′ ) H (12)] and [Pd{η-C 9 H 4 Bn-1-R-2-R′-3}(N-N)]TfO [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 ) bpy (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 Me 2 CdCdCH 2 , CS 2 , or MeNdCdS to give [Pd(η 3 -CMe 2 C{C 6 H(E-CHdCHPh)-6-(OMe) 3 -2,3,4}CH 2 )(tmeda)]Tf O (19), [Pd(S 2 C{C 6 H-(E-CHdCHPh)-6-(OMe) 3 -2,3,4})(tmeda)]TfO (20), or [Pd(SC(NMe){C 6 H(E-CHdCHPh)-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-membered rings are intermediate betwen η 3 and η 5 .

η5-Cyclopentadienylpalladium(II) complexes: Synthesis, characterization and use for the vinyl addition polymerization of norbornene and the copolymerization with 5-vinyl-2-norbornene or 5-ethylidene-2-norbornene

“…2e4, respectively. CpePd distances ( Table 2) are as expected from a comparison to related (h 5 -C 5 H 5 )Pd-phosphine [49,50] and estibine [51], (h 5 -indenyl)Pd-phosphine [52] and eamine [53] complexes. The only other CpPd(C 6 F 5 ) derivative available is (h 5 -C 5 H 5 )Pd(C 6 F 5 )(PPh 3 ) [49].…”

Study of the Reactivity of 2-Acetyl-, 2-Cyano-, 2-Formyl-, and 2-Vinylphenyl Palladium(II) Complexes. Mono- and Triinsertion of an Isocyanide into the Pd−C Bond. A 2-Cyanophenyl Palladium Complex as a Ligand

“…The interest of this subject has prompted us to prepare aryl complexes containing ortho-functionalized aryl groups such as C 6 H(OMe) 3 -2,3,4-X-6 (X )CHO, C(O)Me, CH 2 OEt, C(O)NHBu t ), 13,15-17 C 6 H 3 (CHO) 2 -2,5, 18 C 6 H 4 NH 2 -2, 19-21 and C 6 H 4 OH-2, 22 as well as cyclopalladated primary and secondary benzylamines. 23-25 Some of these complexes have been used as starting materials in reactions with alkynes, 7,13,17,24,[26][27][28] carbon monoxide, 19,20,22,29 isocyanides, 13,21,22,29 and other unsaturated reagents. 30 Recently, we have reported the synthesis of palladium complexes bearing the aryl groups C 6 H 4 X-2 (X ) CHdCH 2 , CHO, C(O)Me, CN).…”

Synthetic analogs of dioncophylline and michellamines by stille coupling

“…These results explain why neutral Alumina must be used instead of Silica gel in case of separation of organo-stannanes [22]. It was proved that the stage of aryl bromide was less capable of supporting the oxidative addition step than aryl iodide [28][29][30][31]. This report clearly shows that the aryl iodide is more reactive than its bromide analogue and that iodide can be efficiently processed through the catalytic cycle when there is a sufficiently reactive, the hetero-metal species present to capture the intermediate of aryl palladium iodide.…”