Synlett 2016; 27(14): 2043-2050
DOI: 10.1055/s-0035-1562236
synpacts
© Georg Thieme Verlag Stuttgart · New York

ortho- and meta-Selective C–H Activation and Borylation of Aromatic Aldehydes via in situ Generated Imines

Ranjana Bisht
Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, Uttar Pradesh 226014, India   Email: buddhadeb.c@cbmr.res.in
,
Buddhadeb Chattopadhyay*
Center of Bio-Medical Research, Division of Molecular Synthesis & Drug Discovery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, Uttar Pradesh 226014, India   Email: buddhadeb.c@cbmr.res.in
› Author Affiliations
Further Information

Publication History

Received: 21 March 2016

Accepted after revision: 14 April 2016

Publication Date:
12 May 2016 (online)


Abstract

A ligand-controlled discovery of ortho and meta C–H boryl­ation of aromatic aldehydes is described. In both cases, an amine is used and it was proposed that ortho borylation could be realized using tert-butylamine as the traceless protecting/directing group and meta boryl­ation undergoes via an electrostatic interaction and a secondary interaction between the ligand of the iridium catalyst and the substrate. Remarkably, these electrostatic interactions and secondary B–N interactions offer a unique and unprecedented guiding factor for the meta-selective C–H activation/borylation of benzaldehydes. This is the first example for the C–H activation and functionalization where the ortho and meta position of a substrate has selectively been functionalized, which open a new chapter in electrophilic aromatic substitution chemistry.

1 Introduction

2 C–H Activation and ortho Borylation of Benzaldehydes

3 C–H Activation and meta Borylation of Benzaldehydes

4 Conclusion