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Herein, we present a CuI-dimer, [CuI{Ph2PC6H4C(O)NC6H4PPh2-o}]2, which catalyzed direct C(sp3)–H homocoupling of benzyl and cycloalkane derivatives with excellent yields and regio-selectivity. The method is very simple and tolerates various functionalities. Synergistic metal–ligand cooperativity was observed in Cu–N bond cleavage and protonation of nitrogen, and facilitates a bifunctional pathway, minimising the free energy corrugation for catalytic intermediates. [ABSTRACT FROM AUTHOR]

Herein, we describe an acid-base-free, sustainable, and efficient method for direct amidation of unactivated alkanes and toluene derivatives, using the dimeric Cu I complex [Cu I { o -Ph 2 PC 6 H 4 CONC 6 H 4 PPh 2 - o } 2 ] (here onward referred to as [PNP-Cu] 2 ). Using this method, C(sp 3 )-N bond formation was achieved through the activation of very challenging C(sp 3 )-H bonds in cycloalkanes, alkenes, allyl groups, and benzyl groups, with tolerance toward ketonic groups, heterocycles, and halide functionalities. One of the precatalysts, (PNHP-Cu-Npht) was isolated and structurally characterized. Isomerization in allyl-functionalized alkanes and selective benzylic alkylation in ketones were observed. This is a novel method for C(sp 3 )-N bond formation via direct N-alkylation of phthalimide, sulfonamide, benzamide, and phosphamidate.

Herein, we present a Cu I -dimer, [Cu I {Ph 2 PC 6 H 4 C(O)NC 6 H 4 PPh 2 - o }] 2 , which catalyzed direct C(sp 3 )-H homocoupling of benzyl and cycloalkane derivatives with excellent yields and regio-selectivity. The method is very simple and tolerates various functionalities. Synergistic metal-ligand cooperativity was observed in Cu-N bond cleavage and protonation of nitrogen, and facilitates a bifunctional pathway, minimising the free energy corrugation for catalytic intermediates.

The reactions of amide functionalized bisphosphine, o -Ph 2 PC 6 H 4 C-(O)N(H)C 6 H 4 PPh 2 - o ( 1 ) (BalaHariPhos), with copper salts is described. Treatment of 1 with CuX in a 1:1 molar ratio yielded chelate complexes of the type [CuX{( o -Ph 2 PC 6 H 4 C(O)N(H)C 6 H 4 PPh 2 - o )}-κ 2 -P,P ] (X = Cl, 2 ; Br, 3 ; and I, 4 ), which on subsequent treatment with KO t Bu resulted in a dimeric complex [Cu( o -Ph 2 PC 6 C(O)(N)C 4 C(O)(N)C 6 H 4 PPh 2 - o )] 2 ( 5 ). Interestingly, complexes 2 - 4 showed weak N-H···Cu interactions. These weak H-bonding interactions are studied in detail both experimentally and computationally. Also, Cu I complexes 2 - 5 were employed in the oxidative dehydrogenative carboxylation (ODC) of unactivated cycloalkanes in the presence of carboxylic acids to form the corresponding allylic esters. Among complexes 2 - 5 , halide-free dimeric Cu I showed excellent metal-ligand cooperativity in the oxidative dehydrogenative carboxylation (ODC) in the presence of carboxylic acids to form the corresponding allylic esters through C( 5 showed excellent metal-ligand cooperativity in the oxidative dehydrogenative carboxylation (ODC) in the presence of carboxylic acids to form the corresponding allylic esters through C( sp 3 )-H bond activation of unactivated cycloalkanes. Mechanistic details of the catalytic process were established by isolating the precatalyst [Cu{( o -Ph 2 C(O)(NH)C 6 H 4 C(O)(NH)C 6 H 4 PPh 2 - o )-κ 2 -P,P }(OOCPh)] ( 6 ) and fully characterized by mass spectrometry, NMR data, and single-crystal X-ray analysis. Density functional theory-based calculations further provided a quantitative understanding of the energetics of a series of H atom transfer steps occurring in the catalytic cycle.