Palladium-Catalyzed Cross-Coupling Reactions: A Powerful Tool for the Synthesis of Agrochemicals

Abstract

Pd-catalyzed cross-coupling reactions have become essential tools for the construction of carbon-carbon and carbon-heteroatom bonds. Over the last three decades, great efforts have been made with cross-coupling chemistry in the discovery, development, and commercialization of innovative new pharmaceuticals and agrochemicals (mainly herbicides, fungicides, and insecticides). In view of the growing interest in both modern crop protection and cross-coupling chemistry, this review gives a comprehensive overview of the successful applications of various Pd-catalyzed cross-coupling methodologies, which have been implemented as key steps in the synthesis of agrochemicals (on R&D and pilot-plant scales) such as the Heck, Suzuki, Sonogashira, Stille, and Negishi reactions, as well as decarboxylative, carbonylative, α-arylative, and carbon-nitrogen bond bond-forming cross-coupling reactions. Some perspectives and challenges for these catalytic coupling processes in the discovery of agrochemicals are briefly discussed in the final section. The examples chosen demonstrate that cross-coupling chemistry approaches open-up new, low-cost, and more efficient industrial routes to existing agrochemicals, and such methods also have the capability to lead the new generation of pesticides with novel modes of action for sustainable crop protection.

Transition‐Metal‐Free Synthesis of Heterobiaryls through 1,2‐Migration of Boronate Complex

“…[1] Besides,b iaryls and heterobiaryls are abundanti nm any marketed drugs [2] like recently approved drug for cancer Rucaparib, Raloxifene [3] (Scheme 1a), agrochemical products, [4] and in light harvesting materials. [1] Besides,b iaryls and heterobiaryls are abundanti nm any marketed drugs [2] like recently approved drug for cancer Rucaparib, Raloxifene [3] (Scheme 1a), agrochemical products, [4] and in light harvesting materials.…”

Shuttling Catalyst: Facilitating C−C Bond Formation via Cross‐Couplings with a Thermoresponsive Polymeric Ligand

“…The vinylation or arylation of alkenes via the Pd-catalyzed reaction was independently discovered by Heck and Mizoroki around 1970, [3b,c] and was widely used in organic synthesis for CÀ C bond formation. [7][8]20] As shown in Scheme 4, MeO-WePhos 5000 was investigated in the Pd-catalyzed Heck reactions, providing a variety of substituted alkenes under biphasic reaction conditions. Electrophiles of aryl and heteroaryl (i. e., thiophene (18) and pyridine (19, 22)) bromides could be successfully transformed into corresponding products in the presence of acrylates and styrene at high isolated yields with 0.1 mol% Pd 2 (dba) 3 .…”

“…Organometallic reagents of organosilicon and organotin were employed as nucleophiles, respectively, in Hiyama and Stille cross-coupling reactions, delivering biaryl units in pharmaceutical, agrochemical and other areas. [7][8]21] Next, the polymeric ligand 4 a was employed in the Hiyama and Stille reactions as shown in Scheme 5. For both types of crosscouplings, aryl, fused aryl and heteroaryl electrophiles were investigated using either PhSi(OEt) 3 or PhSn(Bu) 3 as nucleophiles, providing bi(hetero)aryl products in 86-96 % isolated yields with 0.1 mol% Pd 2 (dba) 3 .…”

“…For example, named reactions including Suzuki-Miyaura, [1] Sonogashira, [2] Heck, [3] Hiyama [4] and Stille [5] reactions have revolutionized avenues to access organic molecules. These homogeneous catalytic processes have been extensively used in both academic and industrial fields, [6] providing important compounds including pharmaceuticals, [7] agrochemicals, [8] natural products, [9] polymer materials [10] and so on. [11] Given the increasing concerns of sustainable development and production costs (i.e., catalyst, purification), many efforts have been devoted to improve the recyclability of catalysts and/or reduce the amount of transition-metal catalysts.…”

Leveraging Fluorescent Emission to Unitary Yield: Dimerization of Polycyclic Aromatic Hydrocarbons

“…[1][2][3][4][5][6][7] Key examples include synthetic bacteriochlorins, [8] mesoÀ meso linked porphyrins, [2] extended naphthofurans, [4] [9] and binaphthyl-derived polymers. [3] [10] Among the different scaffolds, biaryls and its derivatives have certainly attracted the widest interest, as they can be used as ligands for asymmetric catalysis, [11][12][13][14] key structural elements in pharmacologically active substances, [15][16][17] agrochemicals, [17] [18] supramolecular architectures, [19][20][21][22][23][24][25][26] mechanophoresbased sensors, [27] [28] and light-harvesting complexes, [29] [30] to mention a few. In this context, chiral 1,1'-bi-2naphthols (BINOLs) revealed to be a versatile building block for the construction of functional luminescent materials for fluorescent sensors, [31][32][33][34][35][36][37] metal organic frameworks (MOFs), [22] [38] chiral polymers, [10][31]…”