Preparation and Synthetic Applications of [2.2]Paracyclophane Trifluoroborates: An Efficient and Convenient Route to Nucleophilic [2.2]Paracyclophane Cross‐Coupling Building Blocks. Issue 36 (5th September 2019)

• Record Type: Journal Article
• Authors: Knoll, Daniel M.; Šimek, Helena; Hassan, Zahid; Bräse, Stefan
• Is Part Of: European journal of organic chemistry. Issue 36(2019)
• Page Start: 6198
• Page End: 6202
• Publication Date: 2019-09-05
• Subjects: [2.2]Paracyclophane -- Halotrifluoroborates -- Borylation -- Palladium Homogeneous catalysis -- Suzuki‐Miyaura coupling; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201901171
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : 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. Abstract : Preparation and synthetic applications of [2.2]paracyclophane trifluoroborates in the Suzuki–Miyaura cross‐coupling reaction is described. The trifluoroborates and halotrifluoroborates described herein are bench‐stable, crystalline solids accessible on multi‐gram scale and can be cross‐coupled with a wide range of aryl(hetero) halides.