Phosphine‐Directed CH Borylation Reactions: Facile and Selective Access to Ambiphilic Phosphine Boronate Esters

Abstract

Ambiphilic ligands have received considerable attention over the last two decades due to their unique reactivity as organocatalysts and ligands. The iridium-catalyzed CÀH borylation of phosphines is described in which the phosphine is used as a directing group to provide selective formation of arylboronate esters with unique scaffolds of ambiphilic compounds. A variety of aryl and benzylic phosphines were subjected to the reaction conditions, selectively providing stable, isolable boronate esters upon protection of the phosphine as the borane complex. After purification, the phosphine-substituted boronate esters could be deprotected and isolated in pure form.

Rhodium(I)‐Catalyzed Tertiary Phosphine Directed C−H Arylation: Rapid Construction of Ligand Libraries

“…Ther eaction was carried out with CyJohnPhos (1a,1 .0 equiv) and bromobenzene (2a, [*] X. Qiu, [+] (5 mol %) furnished the direct arylation product 3aa in 88 % yield (entry 2). To increase the di-selectivity to am ore synthetically useful level, we increased the reaction temperature to 140 8 8C, and it afforded 4aa in 94 %y ield (entry 8 [18] were completely ineffective in this transformation (entries 11 and 12). An examination of the temperature revealed that amuch lower yield (52 %) was obtained at 80 8 8C(entry 5).…”

Mn(iii)-mediated C–P bond activation of diphosphines: toward a highly emissive phosphahelicene cation scaffold and modulated circularly polarized luminescence

“…Economically, developing synthesis protocols for C-P bond activation from available diphosphines is a concise route for expanding ligand libraries and functional materials. [9][10][11][12][13][14] Nevertheless, the exploitation of efficient activation and reconstruction between C-P and C-H bonds remains a signicant obstruction due to high bonding energy, strong coordinative ability, and intricate selectivity, where noble metal catalysts ([Pd], [Au], and [Rh]) play a critical role. [14][15][16][17][18][19] Morandi's group pioneered the C-P bond activation of diphosphines via Pd 2 (dba) 3 -catalyzed metathesis (Scheme 1a), and the PPh 3 fragment was eliminated for the cyclopalladated intermediate.…”

Rhodium-catalyzed, P-directed selective C7 arylation of indoles

“…Phosphine-metal complexes are usually quite stable and difficult to dissociate. As a result, the docking of a metal to a phosphorous atom in a catalytic C-H activation process is rare (34)(35)(36)(37)(38). Guided by this rationally designed method, here we developed a strategy for the C7 arylation of indoles through rhodium-catalyzed, phosphorous-directed C-H arylation reactions (Fig.…”