Palladium-catalyzed bisfunctionalization of active alkenes by b-acetonitrile-a-allyl addition: application to the synthesis of unsymmetric 1,4-di(organo)fullerene derivatives Shirong Lu a,b , Tienan Jin c,⇑ , Ming Bao a , Abdullah M. Asiri d,e , Yoshinori Yamamoto c,⇑ a State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012, China b Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8548, Japan c Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan d Chemistry Department, Faculty of Science, King Abdulaziz University, PO Box 80203, Jeddah, Saudi Arabia e Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, PO Box 80203, Saudi Arabia article info Article history: Received 27 October 2011 Revised 7 December 2011 Accepted 19 December 2011 Available online 5 January 2012 Keywords: b-Acetonitrile-a-allyl addition Bisfunctionalization of active alkenes All-carbon quarternary center Unsymmetric 1,4-disubstituted C 60 abstract A new, efficient palladium-catalyzed bisfunctionalization of ethylidene malononitriles by addition of ace- tonitrile and allyl groups is developed for the construction of all-carbon quarternary and tertiary centers simultaneously. This methodology is successfully applied to the synthesis of unsymmetric 1,4-disubsti- tuted C 60 . Ó 2011 Elsevier Ltd. All rights reserved. Palladium-catalyzed b-nucleophilic-a-allyl addition of active olefins through p-allyl-palladium intermediates has emerged as a mild and efficient multiple bond-forming method for the simulta- neous construction of all-carbon quaternary and tertiary centers, 1,2 which are important structural units in a wide range of bioactive substances and natural products. 3 Over the past decade, we and other groups have been interested in developing new palladium- catalyzed b-nucleophilic-a-allyl addition reactions toward active alkenes through various p-allyl palladium intermediates, including heteroatom- and carbon-nucleophile addition/allylation, 2e–k bis- allylation, 2a–d acetonation/allylation, 2l,m amidoallylation, 2n and iminoallylation (Fig. 1). 2o The palladium-catalyzed decarboxylative reaction for the formation of p-allyl palladium species is an envi- ronmentally friendly and economical process 1c,4,5 ; the reaction proceeds under essentially neutral conditions with high atom economy. Based on this concept, we envisioned that the bis-p- allylpalladium 2a analogue acetonitrile-(p-allyl)palladium complex should be formed by the reaction of cyanoacetic acid allyl ester with a palladium catalyst, which will undergo acetonitrile/allyl addition to the active alkenes (Fig. 1). Furthermore, in continuation of our interest in transition metal catalyzed functionalization of [60]fullerene (C 60 ), 6 we reasoned that if successful, this methodol- ogy would be applicable to the selective bisfunctionalization of C 60 because of its electrophilic nature and specialized alkene compo- nent. Transition metal catalyzed functionalization of C 60 has emerged as a promising method for preparing functionalized C 60 derivatives with high selectivity and high functional group com- patibility under mild reaction conditions. 7 However, investigations on the synthesis of unsymmetric 1,4-di(organo)fullerenes have been seldom studied, 8 in particular, a one-step catalytic method has not been reported. Herein, we report a new Pd-catalyzed bisfunctionalization of various malononitriles 1 with cyanoacetic acid allyl ester (2), that affords the b-acetonitrile-a-allyl addition products 3 in good to high yields (Eq. 1). Moreover, we have successfully applied this method to the synthesis of unsymmetric 1-acetonitrile-4-allyl- [60]fullerene 4a in good yield in one step. CN CN R O O CN R CN CN CN 5 mol% Pd 2 dba 3 •CHCl 3 20 mol% BINAP THF, rt 1 2 3 + 0040-4039/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.tetlet.2011.12.075 ⇑ Corresponding authors. Tel.: +81 22 217 6177; fax: +81 22 217 6165 (T.J.); tel.: +81 22 217 6164; fax: +81 22 217 5979 (Y.Y.). E-mail addresses: tjin@m.tohoku.ac.jp (T. Jin), yoshi@m.tohoku.ac.jp (Y. Yamamoto). Tetrahedron Letters 53 (2012) 1210–1213 Contents lists available at SciVerse ScienceDirect Tetrahedron Letters journal homepage: www.elsevier.com/locate/tetlet