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A method for dirhodium-catalyzed C(sp3)–H amidation of N , N -dimethylanilines was developed. Chemoselective C(sp3)–H amidation of N -methyl group proceeded exclusively in the presence of C(sp2)–H bonds of the electron-rich aromatic ring. Site-selective C(sp3)–H amidation proceeded exclusively at the N -methyl group of N -methyl- N -alkylaniline derivatives with secondary, tertiary, and benzylic C(sp3)–H bonds α to a nitrogen atom. [ABSTRACT FROM AUTHOR]

A dirhodium-catalyzed, β-selective C–H amination of organosilicon compounds has been developed. Primary C(sp3)–H bonds of silylethyl groups and secondary C(sp3)–H bonds of silacycloalkanes can be selectively converted to C–N bonds at the β-position of the silicon atoms. The experimental data and theoretical calculations indicate that the strong σ-donor ability of the carbon–silicon bonds is responsible for the β-selectivity. Kinetic isotope effects clearly demonstrate that the C–H bond cleavage step is not turnover-limiting, but selectivity-determining. [ABSTRACT FROM AUTHOR]

A dirhodium-catalyzed, β-selective C-H amination of organosilicon compounds has been developed. Primary C(sp 3 )-H bonds of silylethyl groups and secondary C(sp 3 )-H bonds of silacycloalkanes can be selectively converted to C-N bonds at the β-position of the silicon atoms. The experimental data and theoretical calculations indicate that the strong σ-donor ability of the carbon-silicon bonds is responsible for the β-selectivity. Kinetic isotope effects clearly demonstrate that the C-H bond cleavage step is not turnover-limiting, but selectivity-determining.

Although BINOL-derived phosphoric acids are among the most widely used chiral Brønsted acid organocatalysts, their structures are mostly limited to 3,3'-disubstituted ones and simple 3-mono-substituted ones without any polar functionalities on the 3-substituent have not been used in highly enantioselective reactions. This work reports such 3-mono-substituted analogues as effective organocatalysts in direct highly enantioselective Friedel-Crafts-type alkylation of N-unprotected α-ketiminoester. The origin of the observed high enantioselectivity with the 3-mono-substituted catalyst is also discussed., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Direct catalytic C-C bond-forming addition to N-unprotected ketimines is an efficient and straightforward method of synthesizing N-unprotected tetrasubstituted amines that eliminates prior protection/deprotection steps and allows facile transformation of the products. Despite its advantages, however, N-unprotected ketimines have difficulties in C-C bond-forming reactions, and only a limited number of reactions and substrates are reported compared with their N-protected counterparts. Herein we report that N-unprotected trifluoromethyl ketimines are effective for C-C bond-forming reactions using Mannich-type reactions as a model case. We demonstrate that Lewis acid catalysis was effective for promoting reactions with various N-unprotected trifluoromethyl ketimines, and thiourea organocatalysis was effective for promoting highly enantioselective reactions with various carbonyl nucleophiles, providing direct access to various N-unprotected α- and/or β-tetrasubstituted amino acid esters. Furthermore, direct construction of vicinal tetrasubstituted chiral carbon stereocenters was achieved for the first time in a highly enantio- and diastereoselective manner. These results demonstrate the potential of N-unprotected ketimines as substrates applicable to many other addition reactions., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This note describes the construction of tetrasubstituted carbon stereocenters via palladium-catalyzed allylation of sp 3 C-H bonds of 2,2,2-trifluoroethylamine derivatives. The presence of 2-pyridyl group of the imines derived from 1-substituted-2,2,2-trifluoroethylamine was key to promoting the reaction efficiently, allowing an access to a variety of 1-allylated 2,2,2-trifluoroethylamine derivatives with tetrasubstituted carbon stereocenters.

A green way to amino acids: α-Tetrasubstituted α-amino acid derivatives are formed in high yield and enantioselectivity by using a Rh-catalyzed enantioselective alkynylation of α-ketiminoesters. This reaction, which involves a proton transfer and can be conducted at room temperature, has high substrate scope (see scheme; Cbz = benzyloxycarbonyl, Fmoc = 9-fluorenylmethyloxycarbonyl)., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)