A NEW CLASS OF ORGANOCOPPER AND ORGANOCUPRATE COMPOUNDS DERIVED FROM COPPER(I) ARENETHIOLATES

Organometallic reagents (ZR; Z = Li, Mg, or Cu; R = Me, CH2SiMe3, or C6H2Me3-2,4,6) react with copper arenethiolates ([CuSAr]3; SAr = SC6H3(CH(R')NMe2)-2-R"-3 (1, R' = R" = H; 2, R' = Me and R" = H (R-configuration); 3, R' = H and R" = Cl) to give well defined neutral species that have been isolated and characterized both in solution (mol wt determination by cryoscopy and microwave titration, both in benzene, and H-1 NMR) and in the solid state by X-ray crystallography. In these reactions the SAr groups on the copper array are substituted, through interaggregate exchange, by an organic group: [Cu3Li(SAr)3R] (13); [Cu3(SAr)2R]2 (4 and 5); [Cu2(SAr)R]2 (6, 7, and 11); and [Cu4R4][mu-SAr]2[MgSAr]2 (14). Addition of a phosphine ligand to a solution of ZR and [CuSAr]3 provides selective formation of [Cu3(SAr)2(R)(L)] (8, 9, and 12). The latter are postulated as models for the reactive species in the 1,4-addition reaction of organocuprates with alpha,beta-unsaturated carbonyl compounds (L = alkene function). Crystals of [Cu2{SC6H4(CH2NMe2)2}(C6H2Me3-2,4,6)]2 (6) are monoclinic with a = 13.774 (3) angstrom, b = 13.635 (1) angstrom, c = 19.977 (3) angstrom, beta = 109.57 (1)-degrees, V = 3535 (1) angstrom 3, space group P2(1)/n, d(calcd) = 1.550 g cm-3, Z = 4, and R = 0.028 for 6493 reflections with I greater-than or-equal-to 2.5-sigma(I). Crystals of the benzene solvate of [Cu3{SC6H3(CH2NMe2)-2-Cl-3}2(C6H2Me3-2,4,6)(PPh3)] (9) are monoclinic with a = 12.075 (1) angstrom, b = 12.888 (2) angstrom, c = 30.487 (3) angstrom, beta = 93.65 (1)-degrees, V = 4734 (1) angstrom 3, space group P2(1)/c, d(calcd) = 1.475 g cm-3, Z = 4, and R = 0.047 for 7857 reflections with I greater-than-or-equal-to 2.5-sigma(I). Crystals of the toluene solvate [Cu4Mg2{SC6H4(CH(Me)NMe2)-2}4-(C6H2Me3-2,4,6)4] (14) are orthorhombic with a = 25.140 (3) angstrom, b = 19.026 (2) angstrom, c = 8.554 (1) angstrom, V = 4091.5 (8) angstrom 3, space group P2(1)2(1)2, d(calcd) = 1.368 g cm-1, Z = 2, and R = 0.056 for 3674 reflections with I greater-than-or-equal-to 2.5-sigma(I). In solution the organo(arylthiolato)copper compounds 1-16 show fluxional behavior, which could be identified as combinations of three types of intramolecular processes, i.e., inversion of the sulfur configuration (DELTA-G double dagger = 48 kJ mol-1), Cu-N dissociation/association (DELTA-G double dagger = 50-58 kJ mol-1), and a boat-to-boat flip of Cu3S2C and Cu4S2C2 units (DELTA-G double dagger = 40 kJ mol-1), and one intermolecular process, i.e., an interaggregate exchange (DELTA-G double dagger = 70 kJ mol-1).