Synthesis of Nitrogen-Containing 15-Membered Triacetylenic Macrocycles. Stable Complex with Palladium(0)

Abstract

Selective and efficient preparation of a new type of nitrogen-containing 15-membered triacetylenic macrocycles named 1,6,11-tris(arylsulfonyl)-1,6,11-triazacyclopentadeca-3,8,13-triynes (1) (Ar1 = Ar2 = Ar3 = 4-methylphenyl, 1aaa; Ar1 = Ar2 = 4-methylphenyl, Ar3 = ferrocenyl, 1aab) has been achieved. Macrocycle 1aaa forms a very stable complex with Pd0, being the first palladium(0) complex with a macrocyclic triyne. The three triple bonds in 1aaa are responsible for the complexation. The X-ray structures of both the ligand 1aaa and its Pd0 complex are presented. Furthermore, compound 1aaa undergoes cycloisomerization into the corresponding 2,5,8-tris[(4-methlphenyl)sulfonyl]-2,5,8-triazatrindane, 11aaa, when treated with Pd(PPh3)4 in refluxing toluene.

Rhodium(I)‐Catalysed Intramolecular [2+2+2] Cyclotrimerisations of 15‐, 20‐ and 25‐Membered Azamacrocycles: Experimental and Theoretical Mechanistic Studies

“…The whole synthesis started with the reaction of N-tert-butyloxycarbonyl (Boc)-protected p-tolylsulfonamide 5 [28] and 0.5 equiv of 2-butyne-1,4-diol under Mitsunobu reaction conditions to give compound 6. The elimination of the Boc groups in compound 6 (to give 7) and the subsequent treatment with two equivalents of bromo derivative 8 [5] resulted in the isolation of compound 9 with an 80 % yield. The elimination of the Boc groups again with the same reaction conditions as before (TFA in CH 2 Cl 2 ) gave intermediate 10.…”

“…[ [5][6][7][8] When 20-membered macrocycles 3 a-c, heated under reflux in toluene, were treated with [RhCl-…”

“…Partially intramolecular approaches or fully intramolecular cycloaddition processes represent efficient entries into various multiple-fused ring compounds. Over the last few years, we have developed an efficient rhodium(I)-catalysed [2+2+2] cyclotrimerisation process of 15-, 16-and 17-membered triynic and enediynic azamacrocycles of type 1 (to give compounds 2) and have described the first examples in the literature of completed closed systems [5][6][7][8] (Scheme 1). To broad-…”

Recent Advances in Intramolecular Alkyne Cyclotrimerization and Its Applications

“…Later, similar Pd(0)-trialkyne complex 68 was obtained in 56% yield from macrocyclic triyne 67 and 1.1 equiv Pd(PPh 3 ) 4 in THF at room temperature (Scheme 24) [39]. Indeed, the stoichiometric reaction of Pd 2 (dba) 3 with 59 (X = O, R = CO 2 Me) in acetone at room temperature gave rise to a palladabicycle complex.…”

Focusing optics for molybdenum radiation: a bright laboratory source for small-molecule crystallography

“…The crystal was selected on the basis of its diffracting power, such that the diffraction pattern was reasonably intense on the graphite system but did not overload the detector on the confocal system when exposed for the same duration. The full details of the structure determination of this sample have been published elsewhere (Pla-Quintana et al, 2004). Table 2 compares the data obtained for the monochromator and the mirrors.…”