PREPARATION OF AROMATIC IODIDES FROM BROMIDES VIA THE REVERSE HALOGEN EXCHANGE
作者:Hitomi Suzuki、Akiko Kondo、Takuji Ogawa
DOI:10.1246/cl.1985.411
日期:1985.3.5
Aromatic bromides undergo halogen exchange reaction with iodide ion in the presence of copper(I) iodide in hot hexamethylphosphoric triamide, to give the corresponding iodides in good to moderate yields.
and convergent strategy for the assembly of atropisomeric o-terphenyls with 1,2-diaxes via palladium/chiral norbornene cooperative catalysis and axial-to-axial diastereoinduction. Readily available aryl iodides, 2,6-substituted aryl bromides, and potassium aryl trifluoroborates are used as the building blocks, laying the foundation for diversity-orientedsynthesis of these scaffolds (46 examples).
5-ethynylphenyl oligomers were synthesized starting from 3,5-di(trimethylsilylethynyl)phenylacetylene and p-[3,5-di(trimethylsilylethynyl)-1-ethynylphenyl]phenyl acetylene by cross-coupling reaction with a convenient haloaryl derivative, catalyzed by palladium(II)/copper(I), in excellent yield. The terminal acetylenes were efficiently prepared by a specific protection-deprotection methodology. All ethynylphenyl
Using bis(pinacolato)diboron to improve the quality of regioregular conjugated co-polymers
作者:Frank Brouwer、Jan Alma、Hennie Valkenier、Thomas P. Voortman、Jorrit Hillebrand、Ryan C. Chiechi、Jan C. Hummelen
DOI:10.1039/c0jm02359k
日期:——
We demonstrate the use of bis(pinacolato)diboron to directly polymerize symmetric, bisbromo, thiophene-based monomers via a Suzuki homo-polymerization to form co-polymers in less steps than the corresponding co-polymerization. We compare this method to the commonly used Stille co-polymerization by preparing four thiophene-based co-polymers using both methods. We use MALDI-TOF mass spectrometry to show that this new method produces high-quality, uniform polymers with narrow distributions of end-groups. By varying the electronegativity of the monomers, we demonstrate rudimentary control over these end-groups, forming either bis-H-, mono-H-mono-Br-, or bis-Br-terminated polymers in order of increasing electronegativity.
Modular Approach to the Synthesis of Two-Dimensional Angular Fused Acenes
作者:Mikhail Feofanov、Vladimir Akhmetov、Dmitry I. Sharapa、Konstantin Amsharov
DOI:10.1021/acs.orglett.9b04382
日期:2020.3.6
Herein, we present a modular approach to pristine angularly fused planar acenes. The approach includes the Pd-catalyzed fusion of several building blocks and implements a dehydrative π-extension (DPEX) reaction as a key step enabling facile access to diverse two-dimensional acenes. The scope was demonstrated on nine examples with up to quantitative yield.