Molecular Catalysis 442 (2017) 126–132 Contents lists available at ScienceDirect Molecular Catalysis j o ur nal ho me page: www.elsevier.com/locate/mcat Research Paper Palladium supported ionic liquid phase catalyst (Pd@SILP-PS) for room temperature Suzuki-Miyaura cross-coupling reaction Sagar More a , Sanjay Jadhav c , Rajashri Salunkhe b , Arjun Kumbhar a,∗ a Department of Chemistry, P.D.V.P. College, Tasgaon, Sangli, Maharashtra, India b Department of Chemistry, Shivaji University, Kolhapur, Maharashtra, India c CSIR-National Chemical Laboratory, Pune, Maharashtra, India a r t i c l e i n f o Article history: Received 12 February 2017 Received in revised form 21 August 2017 Accepted 31 August 2017 Keyword: Palladium Ionic liquid SILP Immobilization Suzuki-Miyaura reaction a b s t r a c t A new Pd-SILP based on amino functionalized imidazolium ionic liquid immobilized on Merrifield resin (Pd@SILP-PS) has been synthesized. The catalyst was characterized by different techniques like FT-IR, SEM-EDS, TEM, TGA-DTA and XPS. The catalyst has shown to be highly active in Suzuki-Miyaura cross- coupling reaction of various aryl halides and aryl boronic acids in ethanol at room temperature. The activity of catalyst and the nature of product were highly dependent on the type of the solvent used, as well as the substituents present on the aryl halides. The protic polar solvent ethanol gave desired cross- coupling product in good to excellent yields at room temperature. However the aprotic polar solvent THF gave homocoupling product. The catalyst showed at least five times recyclability without a decrease in product yield. © 2017 Elsevier B.V. All rights reserved. 1. Introduction The past few decades have seen rapid development in the area of Pd catalyzed cross-coupling reactions [1,2]. Especially Suzuki- Miyaura cross-coupling reaction [3,4] has been studied more widely owing to the importance of this reaction in the synthesis of many natural products, pharmaceutical intermediates and organic- polymers [5]. As compared to analogous cross-coupling reactions, the Suzuki-Miyaura reaction can be carried out under mild reaction conditions. This reaction has been widely catalyzed by homoge- neous catalysts as these catalysts are highly active [6]. However, the high price of Pd metal and its possible contamination in the final product still overwhelm its use in large-scale applications. To avoid these problems, air-stable, recyclable heterogeneous cata- lysts based on suitable solid supports like carbon, biopolymer, silica, zeolites, organic polymers have been developed [7–11]. In recent years, ionic liquids (ILs) have been engrossed consid- erable interest in transition metal catalysis as a green, non-volatile, recoverable and recyclable reaction media for biphasic reactions, because of the ease of product and catalyst separation [12,13]. There are many reports cited in literature in which IL itself acts as a lig- and in the form of ‘N-Heterocyclic Carbene’ (NHC) complexes [14]. ∗ Corresponding author. E-mail address: arjun22win@rediffmail.com (A. Kumbhar). Nevertheless, due to the substantial amount of ILs are required for biphasic separation and its high preparation cost, many of these ILs are used in very small amounts, in the form of ‘Supported Ionic Liquid Phase’ (SILP).. Though the ‘Supported Liquid Phase Catalysts (SLPC)’ have been reported previously [15], in recent years there is an upsurge in the application of SILP catalysts in many catalytic reactions [16,17]. The concept of SILP involves a formation of thin films of ILs con- taining metal catalysts, on the surface of a suitable solid support. This system leads to a significant decrease in the amount of IL as well as it increases the contact area between the two phases that enhances efficiency of the catalysts. The SILP concept also allows ease of catalyst separation and recycling. This ability of SILP cata- lysts can permit its potential use mainly in fixed-bed reactors [18]. In recent years only few numbers of Pd-SILP catalysts based on organic polymers and silica have been reported for various cross- coupling reactions [19–26]. While only one report mentioned by Gruttadauria et al. [27] for Pd supported on multi-layered, cova- lently supported ionic liquid phase (mlc-SILP) catalyst for the Suzuki-Miyaura cross-coupling reaction in aqueous medium. Recently we reported applications of amine functionalized lig- ands [28] supported on silica [29] as well as alumina-cellulose composite [30] for phosphine-free Suzuki-Miyaura cross-coupling reaction. In this link, we proposed to design highly efficient Pd sup- ported on amine functioned SILP based on Merrifield resin. The conceptual picture of catalyst is represented in Fig. 1. We specu- http://dx.doi.org/10.1016/j.mcat.2017.08.023 2468-8231/© 2017 Elsevier B.V. All rights reserved.