Kilogram-Scale Preparation of an Aminopyrazole Building Block via Copper-Catalyzed Aryl Amidation

Diversification of Pharmaceutical Manufacturing Processes: Taking the Plunge into the Non-PGM Catalyst Pool

Recent global events have led to the cost of platinum group metals (PGMs) reaching unprecedented heights. Many chemical companies are therefore starting to seriously consider and evaluate if and where they can substitute PGMs for non-PGMs in their catalytic processes. This review covers recent highly relevant applications of non-PGM catalysts in the modern pharmaceutical industry. By highlighting these selected successful examples of non-PGM-catalyzed processes from the literature, we hope to emphasize the enormous potential of non-PGM catalysis and inspire further development within this field to enable this technology to progress toward manufacturing processes. We also present some historical contexts and review the perceived advantages and challenges of implementing non-PGM catalysts in the pharmaceutical manufacturing environment.

Ammonia surrogates in the synthesis of primary amines

Primary amines are derivatives of ammonia in which one hydrogen atom is replaced by an alkyl or aryl group. Ammonia serves as the primary nitrogen source in amination reactions, and its utilization in solution or as a pure gas has witnessed notable advancements. However, the use of gaseous ammonia remains problematic in academic laboratory settings, while employing aqueous ammonia poses challenges in highly water-sensitive transformations. Consequently, the search for alternative sources of ammonia has garnered considerable attention among the organic chemistry community. This comprehensive literature review focuses on the use of ammonia surrogates in amination reactions, irrespective of the resulting intermediate. The review emphasizes the formation of the C-N bond and underscores the importance of generating intermediate products that can be readily transformed into primary amines through well-established reactions.

Enabling Suzuki-Miyaura coupling of Lewis-basic arylboronic esters with a nonprecious metal catalyst

The high cost and negative environmental impact of precious metal catalysts has led to increased demand for nonprecious alternatives for widely practiced reactions such as the Suzuki-Miyaura coupling (SMC). Ni-catalyzed versions of this reaction have failed to achieve high reactivity with Lewis-basic arylboron nucleophiles, especially pinacolboron esters. We describe the development of (PPh2Me)2NiCl2 as an inexpensive and air-stable precatalyst that addresses this challenge. Under activation by n-BuMgCl, this complex can catalyze the coupling of synthetically important heteroaryl pinacolborons with heteroaryl halides. Mildly basic conditions (aqueous K3PO4) allow the reaction to tolerate sensitive functional groups that were incompatible with other Ni-SMC methods. Experimental and computational studies suggest that catalyst inhibition by substitution of PPh2Me from Ni(ii) intermediates by Lewis basic reactants and products is disfavored relative to more commonly employed ligands in the Ni-SMC, which allows it to operate efficiently in the presence of Lewis bases such as unhindered pyridines.