AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Palladium-catalyzed direct benzylic C-H arylation of 2-alkyl substituted N-iminopyridinium ylides is described. The insertion can be conducted with several electron-poor and electron-rich aryl chlorides in good yields. This work adds to the few examples of sp(3) C-H insertions that have been reported so far.

Palladium-catalyzed direct C-H arylation of N-iminopyridinium ylides provides a powerful and versatile method for the synthesis of functionalized piperidines in good yields. Chemoselective functionalization of the pyridinium ring in the presence of a pyridine substituent is possible as exemplified by the expedient synthesis of anabasine in 61% overall yield over three steps.

Using a catalytic amount of PdCl2(dppf) x CH2Cl2 in combination with Ag3PO4 and NaOAc, a range of arylated 1,2,3,4-tetrahydropyridines are synthesized in good yields and with complete selectivity at the beta-position. The reaction is compatible with a variety of electron-donating and electron-withdrawing aryl iodides as well as with heteroaryl iodides. The application of these tetrahydropyridines toward the synthesis of polysubstituted piperidines is also demonstrated.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

1,2,3,4-Tetrahydropyridines were halogenated upon treatment with iodine to obtain the desired cross-coupling precursors. Diastereoselective hydrogenation of Suzuki cross-coupling adducts allowed the facile asymmetric synthesis of 2,5-cis-substituted piperidines in five steps from readily available pyridine.

The identification and development of a catalyst for the enantioselective nucleophilic addition of a trifluoromethyl anion to a ketone is described. An easily prepared cinchonine-derived catalyst was used in amounts as low as 4 mol% to afford enantiomeric excess as high as 92%.