Mild, Efficient and Metal‐Free Strategies for Direct Diamination of α, β‐Unsaturated Ketones Using Different Iodine Sources

Abstract

Reaction of α, β‐unsaturated ketone (chalcone) and secondary amine leads to direct diamination of chalcone by dehydrogenation and forming two C−N bonds. This diamination reaction of chalcones with morpholine has been carried out through two effective protocols. The use of N‐iodosuccinimide (NIS) in tetrahydrofuran solvent in one strategy, while the combination of NH2OH ⋅ HCl and NaIO4 in dichloromethane solvent in another are very effective and work at room temperature. No other additives are required for this conversion. Mild and metal free conditions, simple operation technique, good to excellent yields are the notable advantages of both these protocols.

Recent Advancements on Metal‐Free Vicinal Diamination of Alkenes: Synthetic Strategies and Mechanistic Insights

“…), as a cheap and mild oxidizing systems in CH 2 Cl 2 , or N-iodosuccinimide (NIS) [76] in tetrahydrofuran for effective construction of vicinal À N bonds through direct diamination of α,β-unsaturated ketones (Scheme 15). [77] Operational simplicity, good to excellent yields (80-90%), gramscale application, excellent compatibility with structurally and electronically dissimilar α,β-unsaturated ketones 74 a-v and room temperature reactions are the noteworthy advantages features of these strategies. Based on literature reports, [78] the plausible mechanism has been outlined in Scheme 15.…”

Visible-Light-Promoted Metal- and Photocatalyst-Free Reactions between Arylglyoxylic Acids and Tetraalkylthiuram Disulfides: Synthesis of α-Ketoamides

“…In addition, due to low toxicity, mild reactivity, ready availability, high stability, and easy handling, hypervalent iodine reagents have recently received much attention as oxidants in various coupling reactions . Our group is actively engaged in developing various methodologies involving hypervalent iodine reagents as an oxidant . Herein, considering the biological and synthetic importance of α-ketoamides, a simple and convenient approach has been developed for the direct synthesis of α-ketoamides using visible-light-mediated C–N bond-forming reaction of aryl arylglyoxylic acids with N , N , N′ , N′ -tetraalkylthiuram disulfides (TATD) in the presence of (diacetoxy)­iodobenzene (PIDA) under neat conditions (Scheme b).…”

Transition‐Metal‐Catalyzed 1,2‐Diaminations of Olefins: Synthetic Methodologies and Mechanistic Studies

“…Conventionally, vicinal diamination of olefins has been mainly accomplished by transition-metal catalysis [32][33][34][35][36][37][38][39][40][41][42] and iodine-based catalysis [43][44][45] either in an intra-or in intermolecu-lar fashion. Unfortunately, in contrast to the well-established and conceptually analogues aziridinations, [46] dihydroxylation, [47][48] amino-hydroxylations, [49] aminofluorination, [50][51] aminative vicinal difunctionalization has largely remained synthetically underdeveloped. [52] Probably, because of strong chelating effect of 1,2-diamine as ligands.…”