PALLADIUM-CATALYZED ALKYLATIONS IN AQUEOUS-MEDIA

The efficient, catalytic alkylation of biomolecules and other organic substrates in aqueous media has been demonstrated. The water-soluble Pd(0) complex Pd(PPh2(m-C6H4SO3M))3 (2: M = Na+, K+) was isolated and characterized by single-crystal X-ray diffraction. The relevant crystal data for this complex are as follows (M = K+): a = 12.618 (1) Å, b = 19.532 (2) Å, c = 24.423 (3) Å, α = 100.65 (1)°, β = 94.37 (1)°, Γ = 99.10 (1)°; P1, T =-70 °C, dc =1.514 g/cm3, μ = 7.74 cm-1; 14423 reflections; R = 0.054, Rw = 0.053. Crystalline, air-sensitive 2 catalyzed alkylation reactions in a variety of single-phase aqueous solvent systems. Hydrophobic or hydrophilic aryl and heteroaromatic halides underwent coupling reactions with aryl or vinyl boronic acids, alkynes, an alkene, and a dialkyl phosphite. Examples of the alkylation of biomolecules in aqueous media included the coupling of alkynes with unprotected iodonucleotides, iodonucleoside, and an iodoamino acid. This approach provided an alternative, convergent synthesis of T-505, part of a family of chain-terminating nucleotide reagents used in DNA sequencing and labeling. © 1990, American Chemical Society. All rights reserved.