title: Remote para-C-H Functionalization of Arenes by a D-Shaped Biphenyl Template-Based Assembly.
abstract: Site-selective C-H functionalization has emerged as an efficient tool in simplifying the synthesis of complex molecules. Most often, directing group (DG)-assisted metallacycle formation serves as an efficient strategy to ensure promising regioselectivity. A wide variety of ortho- and meta-C-H functionalizations stand as examples in this regard. Yet despite this significant progress, DG-assisted selective para-C-H functionalization in arenes has remained unexplored, mainly because it involves the formation of a geometrically constrained metallacyclic transition state. Here we report an easily recyclable, novel Si-containing biphenyl-based template that directs efficient functionalization of the distal p-C-H bond of toluene by forming a D-shaped assembly. This DG allows the required flexibility to support the formation of an oversized pre-transition state. By overcoming electronic and steric bias, para-olefination and acetoxylation were successfully performed while undermining o- and m-C-H activation. The applicability of this D-shaped biphenyl template-based strategy is demonstrated by synthesizing various complex molecules.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Sukdev
authors.initials: S
authors.lastname: Bag
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Tuhin
authors.initials: T
authors.lastname: Patra
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Atanu
authors.initials: A
authors.lastname: Modak
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Arghya
authors.initials: A
authors.lastname: Deb
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Soham
authors.initials: S
authors.lastname: Maity
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Uttam
authors.initials: U
authors.lastname: Dutta
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Dey
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kancherla
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Maji
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Avijit
authors.initials: A
authors.lastname: Hazra
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Milan
authors.initials: M
authors.lastname: Bera
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay , Powai, Mumbai 400076, India.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Maiti