New Synthetic Strategies and Disconnections in the Synthesis of Liquid Crystals Enabled by Photoredox Cross-Coupling Reactions

TY - JOUR

T1 - New Synthetic Strategies and Disconnections in the Synthesis of Liquid Crystals Enabled by Photoredox Cross-Coupling Reactions

AU - Mandle, Richard

AU - Goodby, John William

N1 - © 2018 Informa UK Limited. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2019

Y1 - 2019

N2 - In this letter we describe the application of metallaphotoredox cross-electrophile couplings to the synthesis of liquid crystals using dual nickel and iridium catalysis. Given the proliferation of aryl and alkyl bromides in liquid crystal research we consider that the silyl-radical mediated cross coupling of alkyl bromide with an aryl bromide (to afford a direct alkyl-aryl bond) will become an extremely powerful tool in the synthesis of liquid crystalline materials, and we use this to synthesise several well-known materials (PCH32, 5CB, CB7CB and CB15) in a single synthetic step from inexpensive and commercially available building blocks. The metallaphotoredox decarboxylative sp3-sp2 cross-coupling of an aryl bromide with an alkyl carboxylic acid provides a complimentary method to form alkyl-aryl bonds, and we use this to successfully prepare trans PCH5 in a single synthetic step from commercially available building blocks. We also prepare novel methylene linked materials in a single synthetic step, one of which exhibit the topical TB phase.

AB - In this letter we describe the application of metallaphotoredox cross-electrophile couplings to the synthesis of liquid crystals using dual nickel and iridium catalysis. Given the proliferation of aryl and alkyl bromides in liquid crystal research we consider that the silyl-radical mediated cross coupling of alkyl bromide with an aryl bromide (to afford a direct alkyl-aryl bond) will become an extremely powerful tool in the synthesis of liquid crystalline materials, and we use this to synthesise several well-known materials (PCH32, 5CB, CB7CB and CB15) in a single synthetic step from inexpensive and commercially available building blocks. The metallaphotoredox decarboxylative sp3-sp2 cross-coupling of an aryl bromide with an alkyl carboxylic acid provides a complimentary method to form alkyl-aryl bonds, and we use this to successfully prepare trans PCH5 in a single synthetic step from commercially available building blocks. We also prepare novel methylene linked materials in a single synthetic step, one of which exhibit the topical TB phase.

KW - NTB

KW - Synthesis

KW - liquid crystals

KW - photoredox

KW - twist-bend

UR - http://www.scopus.com/inward/record.url?scp=85046797931&partnerID=8YFLogxK

U2 - 10.1080/02678292.2018.1468504

DO - 10.1080/02678292.2018.1468504

M3 - Article

SN - 0267-8292

VL - 46

SP - 4

EP - 10

JO - LIQUID CRYSTALS

JF - LIQUID CRYSTALS

IS - 1

ER -