A biomass-derived safe medium to replace toxic dipolar solvents and access cleaner Heck coupling reactions

Abstract

γ-Valerolactone (GVL) is an excellent reaction medium, derived from biomasses, which can replace classic dipolar aprotic media such as DMF or NMP.

Scope and limitations of a DMF bio-alternative within Sonogashira cross-coupling and Cacchi-type annulation

“…In addition to its renewability, Cyrene, as yet, has no associated pernicious effects and could potentially represent a direct and functional replacement in many of the fundamental reactions that typically employ DMF [31–32]. The replacement of solvents with regulatory issues with bio-derived alternatives has provided a series of advances within the cross-coupling arena [33], allowing efficient C–C bond formation via cornerstone Pd-based methods including Suzuki–Miyaura [34–35], Mizoroki–Heck [36–37], Sonogashira [38], Stille [39], Hiyama reactions [40], and hydroformylation reactions [41]. …”

Intelligent Approach to Solvent Substitution: The Identification of a New Class of Levoglucosenone Derivatives

“…This family of solvents have as traightforwardc hemical synthesis (Scheme 3), and have notably higher d P values than the Cygnets ( Figure 1). [8] The ester functionality of the lactones can be considered as aw eakness, but there is as imilar problem with the potentially reactive ketone of Cyrene. [8] The ester functionality of the lactones can be considered as aw eakness, but there is as imilar problem with the potentially reactive ketone of Cyrene.…”

“…The other possible NMP replacements in Figure 3 are synthetically complex and include iso-levoglucosenone and the equivalent constitutionalisomero fC yrene. The development of hydroxylac-tones elsewhere [28] and the previous discovery of Cyrene, [7] g-valerolactone, [8] and cyclic carbonates [9] as viable NMP replacements meantt hat after consideration only the Cygnet family of compounds was carriedf orward for further analysis. The development of hydroxylac-tones elsewhere [28] and the previous discovery of Cyrene, [7] g-valerolactone, [8] and cyclic carbonates [9] as viable NMP replacements meantt hat after consideration only the Cygnet family of compounds was carriedf orward for further analysis.…”

“…There has been some very recent but limited progressi nt he search for greener polar aprotics olvents withoutt he functionalities associated with human toxicity, [7][8][9] but because each substitute falls into as pecific niche more alternatives are required. Bio-based solvents have begun to generate significant interesti na cademic studies and across an umber of chemical industries.…”

Definition of green synthetic tools based on safer reaction media, heterogeneous catalysis, and flow technology

“…Our first application of GVL as reaction medium was in the Mizoroki-Heck reaction catalyzed by commercially available Pd/C (0.1 mol%) [29]. Iodoarenes 1 and styrenes or acrylates 2 reacted in the presence of 1 equiv.…”