Enantio‐ and Diastereoswitchable C−H Arylation of Methylene Groups in Cycloalkanes

Abstract

A complementary set of chiral N,N‐ligands enables the Pd‐catalyzed β‐C−H arylation of unbiased internal methylene groups in good yield and with high levels of enantio‐ and diastereoinduction. Both the dia‐ and enantioselectivity can be reversed, thus allowing the selective arylation of any of the four β‐C−H bonds in cycloalkanecarboxamides of various ring sizes. The method is applicable to a broad range of aryl iodides with electron‐withdrawing and ‐donating substituents in the o‐, m‐, or p‐position.

Recent Advances in the Application of Vibrational Circular Dichroism Spectroscopy for the Characterization of Asymmetric Catalysts

“…As this “misplacement” of the bands affects the overall appearance of vibrational spectra, a detailed one‐to‐one comparison with experimental spectra is usually not possible. Luckily we found that the M06‐2X functional performs quite well in the prediction of C–F vibrational frequencies, which is in fact due to a compensation of errors, so that we could finally turn our attention to more realistic thiourea catalysts.…”

“…In the context of asymmetric catalysis, VCD spectroscopy is more and more considered for reliable AC assignments of new compounds. [6,21] In the case of 8 (cf. Scheme 2), it has even been used to determine the AC of the novel asymmetric catalyst itself.…”

“…European Journal of Organic Chemistry tion of C-F vibrational frequencies, [21] which is in fact due to a compensation of errors, [35] so that we could finally turn our attention to more realistic thiourea catalysts.…”

Diastereoselective palladium-catalyzed functionalization of prochiral C(sp3)–H bonds of aliphatic and alicyclic compounds

“…Similarly, Colobert reported 34 the enantioselective preparation of compound 19d by using N -protected aminosulfoxide 19c as the chiral ligand. Recently, Gooßen and Yu demonstrated 35 an elegant concept that both diastereoselectivity and enantioselectivity can be reversed by choosing an appropriate ligand. Accordingly, the β-C–H arylation of carboxamide 20a with ligands 20d or 20e afforded the enantiopure carboxamides 20b and 20c , respectively (Scheme 5).…”

Synthesis of Acyclic Aliphatic Amides with Contiguous Stereogenic Centers via Palladium‐Catalyzed Enantio‐, Chemo‐ and Diastereoselective Methylene C(sp3)−H arylation

“…; a-diethyl, 3:1 d.r., ee unchecked). [9,10] The flexibility of acyclic systems necessitates the judicious choice of proper chiral ligand and DG to enable the efficient stereoinduction and tune the reactivity. Herein, we describe our solution to this challenge by the combination of bidentate 2-pyridinyisopropyl (PIP) auxiliary and 3,3'-F 2 -BINOL.…”