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Preparation and Synthetic Applications of [2.2]Paracyclophane Trifluoroborates: An Efficient and Convenient Route to Nucleophilic [2.2]Paracyclophane Cross‐Coupling Building Blocks
Author(s) -
Knoll Daniel M.,
Šimek Helena,
Hassan Zahid,
Bräse Stefan
Publication year - 2019
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201901171
Subject(s) - chemistry , moiety , combinatorial chemistry , nucleophile , aryl , regioselectivity , reagent , borylation , coupling reaction , coupling (piping) , organic chemistry , catalysis , alkyl , mechanical engineering , engineering
We report the synthesis of [2.2]paracyclophane (PCP) trifluoroborate building blocks that can be used for the incorporation of the PCP moiety into a wide range of (hetero)aryl chlorides, bromides and triflates by a Pd(II)/RuPhos mediated Suzuki–Miyaura cross‐coupling reaction. The PCP trifluoroborate species are bench stable with extended shelf life and easily accessible on a multigram scale by a two‐step synthesis from commercially available PCP. They can be handled conveniently without special precautions, thus overcoming many of the limitations of other PCP cross‐coupling reagents. Additionally, a high yielding regioselective monolithiation/borylation protocol for the synthesis of pseudo‐ para and pseudo‐ ortho PCP halotrifluoroborates and their subsequent Suzuki–Miyaura cross‐coupling are described.