Metal Template Synthesis of a 14-Membered trans-P2S2 Chelating Macrocycle

Abstract

The R*,R* and R*,S* forms of the 14-membered trans-P2S2 chelating macrocycle 5,6,7,9,14,15,16,18-octahydro-5,14-dimethyldibenzo[e,l][l,8,4,ll]dithiadiphosphacyclotetradecin have been isolated in low yields from the dimerization of deprotonated (±)-(2-mercaptoethyl)(2-methoxybenzyl)methylphosphine on platinum(II) in the presence of boron tribromide. The crystal structure of the monoacetone solvate of the nickel(II) perchlorate derivative of the R*,R* diastereomer of the macrocycle has been determined. Crystal data for C23H32Cl2NiOsP2S2: monoclinic, P21/n, a = 8.988 (1) Å,b = 23.660 (3) Å, c = 14.257 (2) Å, β = 94.15 (1)°, Z = 4, and R = 0.040. The complex is formed stereoselectively with the relative helicities of the four chiral donor stereocenters being R*f, R*r, S*s, and S*s because of exo coordination of the nickel(II) ion to the macrocyclic ring. The byproducts of the metal-template synthesis are seven-membered (±)-2-methyl-2-phospha-5-thiabicyclo[5.4.0]undeca-l(7),8,10-triene and its boron tribromide adduct; the latter is the principal product of the reaction, and its crystal structure has been determined. Crystal data for C10H13BBr3PS; monoclinic, P21/c, a = 14.200 (2) Å, b = 17.074 (3) Å, c = 13.429 (2) Å, ² = 113.14 (1)°, Z = 8, and R = 0.038. Show more