Enhanced Reactivity by Torsional Strain of Cyclic Diaryliodonium in Cu-Catalyzed Enantioselective Ring-Opening Reaction

Abstract

An efficient method is developed for preparing functionalized axially chiral compounds via the ring-opening reaction of cyclic diaryliodonium salts. Two conformers of the cyclic diaryliodonium salt observed in the crystal structure underwent quick equilibration. The distortion of the diaryliodonium salts significantly increased reactivity toward the chiral copper catalyst, which enabled the reaction to take place in mild conditions to furnish the products in enantioselectivities up to 99.5:0.5 (R:S).

Tailorable synthesis of heterogeneous enzyme–copper nanobiohybrids and their application in the selective oxidation of benzene to phenol

“…Copper is a low cost and earth-abundant metal, which has been described as being very useful for different applications, [1][2][3][4][5] especially catalysis. [6][7][8][9] In terms of the different Cu compounds available, copper nanoparticles (CuNPs) have generated great interest in recent years. 10 The high surface-tovolume ratio of nanomaterials compared to bulk materials generally makes them attractive candidates for application as catalysts.…”

Unusual biaryl torsional strain promotes reactivity in Cu-catalyzed Sommelet–Hauser rearrangement

“…The torsional angle (C5–C6/C7–C13) was around 41° in F and 29° in G . 19 Steric repulsion between the two ortho -substituents increased the distortion in the biaryl structure. We reasoned that the two ortho -substituents in E should distort its structure to a similar extent as in F .…”

Atom‐Economical Applications of Diaryliodonium Salts

“…Recently, the Gu group developed a Cu‐bis(oxazolinyl)pyridine‐catalyzed asymmetric ring‐opening amination of five‐membered cyclic diaryliodonium salts for the synthesis of axially chiral biaryliodides (Scheme ) . A broad range of electron‐donating and electron‐withdrawing group substituted aniline derivatives were successfully achieved.…”

“…Recently,t he Gu group developedaCu-bis(oxazolinyl)pyridine-catalyzed asymmetric ring-opening aminationo ff ivemembered cyclic diaryliodonium salts for the synthesis of axially chiral biaryliodides (Scheme 14). [15] Ab road range of electron-donating and electron-withdrawing group substitutedaniline derivatives were successfully achieved. Trifluoromethanesulfonamidew as also compatible with the copper-catalyzed ring-opening reaction, and the desired product wasp rovided with satisfactory enantioselectivity.V arious benzylamines displayedg ood compatibility,a nd their asymmetric ring-opening amination reactions were conducted to afford the corresponding products in high yields and excellent ee.…”