Uncovering the mechanism leading to the synthesis of symmetric and asymmetric Tröger's bases

PRISCILA A. LANZA; DIEGO DUSSO; CRISTINA L. RAMIREZ; ALEJANDRO R. PARISE; CARLOS A. CHESTA; E. LAURA MOYANO; D. M. A.VERA*

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2019

1434-193X

Tröger´sbaseshave been attracting great interest due to their potentialapplications in nanoelectronics, supramolecularchemistry, molecularrecognition, biologicalactivityand auxiliariesfor asymmetric synthesis.However,a detailed step by step proposal forthe mechanism leading to the production of these compounds isstill uncovered. Aset of five model syntheses of symmetric and asymmetric Tröger´sbase derivatives startingfrom substitutedanilines and formaldehyde wasdoneand envisagedas representative for understanding the underlying mechanism. Allreasonable pathways were thoroughly scanned bymeans of DFT calculations. Thehighest energy TSwasassociated with the entrance of the first formaldehyde which producesthe first out of three key carbocations. The last step, theclosureof the methylene-bridgeddiazocyne heterocycle was also found of kinetic relevance andasa source of stable intermediates or byproducts. Thewhole mechanistic picture would provide keys for the rationalplanning of the synthesis of these compounds.p { margin-top: 0.15cm; margin-bottom: 0.15cm; line-height: 150%; text-align: justify; break-before: auto; }p.western { font-family: "Times New Roman", serif; }p.cjk { font-size: 10pt; }a:link { }