Au-Catalyzed Hexannulation and Pt-Catalyzed Pentannulation of Propargylic Ester Bearing a 2-Alkynyl-phenyl Substituent: A Comparative DFT Study

Abstract

The mechanistic pathways of metal-catalyzed pentannulation and hexannulation of aromatic enediyne were studied quantum mechanically with Pt and Au salts. In agreement with the experimental facts, our result shows that the pentannulation favors over the hexannulation under Pt-catalyzed conditions and the reverse possibility favors when the Pt salt is replaced with an Au one. The Pt-catalyzed reaction involves a long-range acyl migration that follows the cyclization step. Our study reveals that such migration takes place under the assistance of a ligand of the metal atom. Moreover, the variation of aromaticity (probed by the change of the nucleus-independent chemical shift (0) value) in the cyclization steps shows that both processes maintain the development of the aromatic character of the generated intermediate during the progress of the reaction.

Theoretical Study on the Mechanism of Rearrangement Reactions of Bicyclic Derivatives of Cyclopropane to Monocyclic Derivatives under the Catalysis of Pt-Salt

“…All calculations were carried out with the Gaussian 09 computational program package. 12 Geometry optimization of all species 13 was performed using M06-2X functional 14 in the DFT method. The 6-31G(d,p) basis set 15 was employed for all nonmetal atoms and the LANL2DZ basis set 16 was employed for the Pt atom.…”

Aza-Henry Reaction: Synthesis of Nitronaphthylamines from 2-(Alkynyl)benzonitriles

“…However, the applicability of this approach address some issues related to regioselectivity, multistep procedures, harsh reaction conditions, and tolerance of pre-existing functional groups, thereby limiting their applicability in synthetic chemistry. , For the synthesis of naphthalene core, annulation of integrally functionalized benzene precursors was developed successfully, consequently avoiding the necessity of less available prefunctionalized naphthalene precursors . As such, many strategies came into existence, such as annulations of alkynes, alkenes, allenes, fischer carbenes, ynones etc. ; however, routes to access amine- or nitro-containing naphthalenes are often limited .…”