MeOH OMe OMe "Pd" + + butadiene dimers 1 2 N SO 2 Ar N N ArO 2 S SO 2 Ar N SO 2 Ar N N ArO 2 S SO 2 Ar Pd Pd-Ma: Ma: Ar = 2,4,6-tri-i-propylphenyl TETRAHEDRON LETTERS Tetrahedron Letters 42 (2001) 7055–7057 Pergamon 15-Membered macrocyclic triolefin: role in recovering active palladium catalyst for the telomerization of butadiene with methanol Boris Estrine, a Bele ´n Blanco, b Sandrine Bouquillon, a Franc ¸oise He ´nin, a, * Marcial Moreno-Man ˜ as, b Jacques Muzart, a Carolina Pena a,b and Roser Pleixats b a Unite ´ Mixte de Recherche Re ´actions Se ´lectives et Applications, CNRS, Universite ´ de Reims Champagne, Ardenne, BP 1039, 51687 Reims Cedex 2, France b Department of Chemistry, Universitat Auto `noma de Barcelona, Cerdanyola, 08193 Barcelona, Spain Received 19 June 2001; accepted 6 August 2001 Abstract—The 15-membered macrocyclic triolefin Ma stabilizes a Pd(0) catalyst, active and recyclable in telomerization of butadiene with methanol. This Pd catalyst is generated from different Pd(0) or Pd(II) sources associated with phosphanes. © 2001 Elsevier Science Ltd. All rights reserved. Recently, palladium(0) complexes of 15-membered macrocyclic triolefins, represented in Fig. 1 as Pd-Ma, have been synthezised 1 and shown to be efficient and recoverable catalysts for Suzuki-type cross-coupling reactions. 2 We were interested in using such a recover- able catalytic system in telomerization of butadiene in the presence of nucleophiles such as methanol 3 (Eq. (1)); this transformation remains of interest due to the possible use of linear octadienyl derivates as building blocks in the synthesis of natural products. 4 Many homogeneous zerovalent and bivalent palladium com- plexes excel in efficiency and selectivity in telomeriza- tion, 3,5 whose mechanism has been recently revisited. 6 However, no example of soluble recyclable systems seems to be reported. Only polymer-bound palladium complexes could be easily separated from a reaction mixture and reused with some loss of the activity 7 or with its preservation. 8 We present here our first results in recycling a soluble catalyst starting from different palladium sources associated with the free triolefinic macrocycle Ma. (1) We started our studies with Pd-Ma as catalyst (Table 1, entries 1–7) and compared the results with those observed by using Pd 2 (dba) 3 ·CHCl 3 (noted below Pd- dba) as catalytic precursor (Table 1, entries 8–11), or Pd(OAc) 2 (Table 1, entry 12). Pd-Ma exhibited no efficiency without added phosphane (entry 1). The butadiene conversion was enhanced in the presence of Figure 1. Structures of Pd-catalyst and macrocyclic ligand. * Corresponding author. Fax: 33 3 26 91 31 66; e-mail: francoise.henin@univ-reims.fr 0040-4039/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved. PII:S0040-4039(01)01464-2