A palladium-catalyzed one-pot amino-sulfonylation of aryl iodide derivatives with thiourea dioxide, PdCl2dppf, and one-pot added hydroxylamine-O-sulfonic acid is presented. This amino-sulfonylation gave structure diversity to aryl primary sulfonamides and features good functional group compatibility, mild reaction conditions, excellent regioselectivity, and moderate to good yields. The robustness and potential of this method have also been successfully demonstrated by late-stage elaboration and gram-scale reaction. This approach achieves the divergent construction of the complex core structures that are prevalent in highly valuable natural products such as Sulpiride, Venetoclax, and Furosemide.
Aminals, characterized by a central carbon linking two nitrogen atoms, are versatile building blocks in modern chemistry. This review addresses a literature gap by exploring the synthesis and applications of aminals, with a focus on drug discovery and molecular diversity. Beyond medicinal chemistry, aminals find applications as key components in bioactive compounds and as versatile tools in materials chemistry. The review covers fundamental characteristics, synthetic methodologies, stability, and applications, emphasizing alternative synthetic methods to the well-established aldehyde–amine condensation. This inclusive exploration provides insights into diverse synthetic pathways that expand the versatility of the aminal scaffold.
1 Introduction
2 The Aminal Group
3 Aminal Synthesis
3.1 Metal-Free Approaches
3.2 Metal-Catalyzed Approaches
3.3 Photoredox Methodologies
3.4 Via Rearrangements
3.5 Via Decarboxylative Coupling
4 Aminals as Synthetic Tools
5 Synthesis of Aminal-Containing Natural Products
6 Aminal-Based Materials
7 Conclusions
An efficient heterogeneous palladium-catalyzed carbonylative coupling of aryl halides and organoaluminum compounds has been developed using tert-butyl isocyanide as CO equivalent. The carbonylation reaction proceeds smoothly in toluene with KOtBu as a base at 100 °C by using 10 mol% of an SBA-15-anchored bidentate phosphine palladium(0) complex [2P-SBA-15-Pd(0)] as the catalyst and provides a general and practical approach for the assembly of 1,2-diketones in good to excellent yields. This heterogenized palladium catalyst can be readily separated and recovered via a simple centrifugation process and reused for more than seven cycles with almost consistent catalytic efficiency.