Regioselective ortho palladation of stabilized iminophosphoranes in exo positions: Scope, limitations, and mechanistic insights

David Aguilar, Raquel Bielsa, María Contel, Agusti Lledós, Rafael Navarro, Tatiana Soler, Esteban P. Urriolabeitia

Research output: Contribution to journalArticleResearchpeer-review

36 Citations (Scopus)

Abstract

The reactivity of the stabilized iminophosphoranes R3P=NC(O)Ph (R = p-tolyl, m-tolyl), Ph3P=NC(O)CH2Ph, and Ph 2P(CH2)nPPh2=NC(O)Ph (n = 1, 2) toward Pd(OAc)2 has been examined. These substrates undergo palladation at the ortho C(sp2)-H bond of the benzamide ring, giving exo complexes with complete regioselectivity. The mechanism of this reaction has been studied using DFT calculations and the regioselectivity explained on a kinetic basis, since the activation barrier is lower for the exo pathway than for the endo. The origin of this lower energy for the exo barrier seems to reside mainly on the interaction energy between the metal center and the ligand at the transition state. On the other hand, the palladation of the related keto-stabilized systems Ph3P=NC(O)FG (FG = NC4H 8, NC4H8O) gives selectively the endo isomers through C-H bond activation at the Ph ring of the PPh3 unit. © 2008 American Chemical Society.
Original languageEnglish
Pages (from-to)2929-2936
JournalOrganometallics
Volume27
Issue number13
DOIs
Publication statusPublished - 14 Jul 2008

Fingerprint Dive into the research topics of 'Regioselective ortho palladation of stabilized iminophosphoranes in exo positions: Scope, limitations, and mechanistic insights'. Together they form a unique fingerprint.

Cite this