Atropisomerism in azadipeptides: evaluation of N-1-methylation and thioamide introduction

作者：Otter**ach Philipp A; Schnakenburg Gregor; Guetschow Michael

来源：Tetrahedron Letters, 2015, 56(34): 4889-4891.

DOI：10.1016/j.tetlet.2015.06.074

• Atropisomers
• Azapeptides
• Diastereotopicity
• Peptide thioamides

Cbz-protected azadipeptides, designed as structurally reduced model compounds, were synthesized and investigated with respect to the occurrence of atropisomerism. Methylation at the carbamate nitrogen caused mixtures of E and Z isomers in Cbz-sarcosyl-azaglycine-amide (9) and Cbz-sarcosyl-methylazaala-nine-amide (10). A formal O/S exchange led to Cbz-glycyl-azaglycine-thioamide (11) and Cbz-glycyl-methylazaalanine-thioamide (12), respectively. The (MeN)(2) fragment, present in 10 and 12 (but not 9 and 11), serves as a chirality-inducing element owing to a restricted rotation around the N-N axis.

• 出版日期2015-8-19