Intramolecular SN'-type aromatic substitution of benzylic carbonates at their para-position

Satoshi Ueno; Sadakazu Komiya; Takeshi Tanaka; Ryoichi Kuwano

doi:10.1021/ol203089k

Intramolecular SN'-type aromatic substitution of benzylic carbonates at their para-position

Org Lett. 2012 Jan 6;14(1):338-41. doi: 10.1021/ol203089k. Epub 2011 Dec 2.

Authors

Satoshi Ueno¹, Sadakazu Komiya, Takeshi Tanaka, Ryoichi Kuwano

Affiliation

¹ Department of Chemistry, Graduate School of Sciences, and International Research Center for Molecular Systems (IRCMS), Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.

PMID: 22136586
DOI: 10.1021/ol203089k

Abstract

The benzylic carbonates, which connect with an active methine through an o-phenylene tether at their meta-position, are cyclized by Pd(η(3)-C(3)H(5))Cp-S-Phos catalyst, yielding 3-methyl-9,10-dihydrophenanthrenes. In the catalytic cyclization, the internal nucleophile attacks not the ortho-carbon but the para-carbon of the benzylic ester. The [3 + 2] cycloaddition of m-(silylmethyl)benzyl carbonates with alkylidene malonates was developed from the palladium-catalyzed intramolecular S(N)'-type aromatic substitution.