Suzuki reaction of tribromo‐2,6‐lutidine with (2‐methoxyphenyl)boronic acid gave 3,4,5‐tris(2‐methoxyphenyl)‐2,6‐lutidine in the form of a mixture of three atropisomers that were stable at room temperature. Each isomer was isolated and fully characterized, including by X‐ray structure determination. One of the isomers, being a racemic mixture, was separated into individual enantiomers by using semipreparative chiral HPLC. Their absolute stereochemistry was initially assigned on the basis of computational calculation of the CD spectra and finally confirmed by X‐ray analysis.

The electron ionization-induced fragmentation patterns of three forensically relevant Schiff bases, originating from the condensation between 2-, 3- and 4-methoxyamphetamine and the corresponding ketones, were studied. The proposed fragmentation routes and ion structures are supported by high-resolution data and B/E linked-scan and mass-analyzed ion kinetic energy spectra. The rationalization of the ortho effect, which is responsible for the formation of the [M-OCH3] fragment in the case of the imine bearing ortho-substituted methoxy group, is given.

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SummaryA series of differently substituted 3,5-diaryl-2,4,6-trimethylpyridines were prepared and characterized using the Suzuki–Miyaura coupling reaction with accordingly selected bromo-derivatives and arylboronic acids. The reaction conditions were carefully optimized allowing high yield of isolated products and also the construction of unsymmetrically substituted diarylpyridines, difficult to access by other methods.

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L‐Amino acids (L‐Ala, L‐Phe, L‐Val, L‐Pro) were used as a source of chirality in the diastereoselective synthesis of tetrahydroisoquinoline derivatives. The key step was the Pictet−Spengler condensation of ketoamides 4 and 10, which proceeded under very mild conditions. L‐Ala, L‐Phe and L‐Val gave rise the R‐configuration at the newly formed stereogenic center. Surprisingly, L‐Pro gave the opposite result. The stereochemistry of 6d and 12a were established on the basis of X‐ray crystallographic data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The Suzuki–Miyaura reaction of 4‐amino‐3,5‐dibromo‐2,6‐lutidine with various ortho‐substituted phenylboronic acids resulted in the formation of a series of mono‐ and diarylated lutidines in the form of atropisomers. The absolute stereochemistry of the chiral compounds was established, in some cases, by X‐ray crystal structure analysis and HPLC‐ECD (ECD = electronic circular dichroism) in combination with time‐dependent density functional theory (TDDFT) calculations.