REACTIONS OF (C5ME5)RH(PME3)(R)H WITH ELECTROPHILES - INSERTION OF UNSATURATED MOLECULES INTO ACTIVATED CARBON HYDROGEN-BONDS

The complexes (C5Me5)Rh(PMe3)(aryl)H (aryl = C6H5, 2,6-C6H3Me2) are found to react with several electrophiles. Treatment with CS2 gives two products, the major species resulting from the elimination of benzene and formation of (C5Me5)Rh(PMe3)(CS2). The minor product is formed by insertion into the Rh‒H bond to give (C5Me5)Rh(PMe3)(Ph)(SCH═S). Reaction of the aryl hydride complex with PhNCS gives only the insertion product (C5Me5)Rh(PMe3)(Ph)(SCH═NPh). These two sulfur-bound derivatives react with either aniline or H2S, respectively, to give (C5Me5)Rh(PMe3)(Ph)[SCH(SH)(NHPh)], which cleaves during isolation to give (C5Me5)Rh(PMe3)(Ph)(SH) and PhNHCH═S. Reaction of the aryl hydride complex with dimethyl acetylenedicarboxylate results in insertion of acetylene into the Rh‒H bond, producing a mixture of the cis and trans vinyl complexes. HI cleaves the rhodium‒aryl bond, and iodine induces both elimination of substituted styrene and iodination of the metal‒xylyl bond in the cis complex. Treatment of the trans isomer with HI also cleaves the Rh‒aryl bond, and iodine gives a mixture of products. The methyl complex (C5Me5)Rh(PMe3)(CH3)H reacts with dimethyl acetylenedicarboxylate to give a mixture of cis and trans vinyl methyl complexes. Addition of iodine results in the formation of methyl iodide and (C5Me5)Rh(PMe3)[C(COOMe)═CH(COOMe)]I. cis-(C5Me5)Rh(PMe3)(2,6-C6H3Me2)[C(COOMe)═CH(COOMe)] crystallizes in the triclinic space group P1 with a = 8.928 (5) Å, b = 19.111 (4) Å, c = 8.590 (2) Å, α = 94.21 (2)°, β= 111.86 (4)°, γ = 94.08 (3)°, V = 1348.9 (1.8) Å3, and Z = 2. trans-(C5Me5)Rh-(PMe3)[C(COOMe)═CH(COOMe)](2,6-C6H3Me2) crystallizes in the monoclinic space group P21/n with a = 15.090 (2) Å, b = 11.361 (2) Å, c = 16.886 (4) Å, β = 109.54 (2)°, V = 2728.4 (1.8) Å3, and Z = 4. © 1990, American Chemical Society. All rights reserved.