Photochromism of Arylchromenes: Remarkable Modification of Absorption Properties and Lifetimes of o-Quinonoid Intermediates
摘要:
A significant pi-conjugation in 6- and 7-arylchromenes manifests dramatically in the absorption properties of their photogenerated o-quinonoid intermediates. This in conjunction with facile synthesis via Suzuki coupling may render a myriad of photochromic arylchromenes with wide-ranging spectrokinetic properties readily accessible.
Directed Ortho Metalation Methodology. The <i>N</i>,<i>N</i>-Dialkyl Aryl <i>O</i>-Sulfamate as a New Directed Metalation Group and Cross-Coupling Partner for Grignard Reagents
作者:Todd K. Macklin、Victor Snieckus
DOI:10.1021/ol050393c
日期:2005.6.1
with a variety of electrophiles constitutes a new generalroute to substituted aryl O-sulfamates 4a-k. The Kumada-Corriu cross-coupling of O-sulfamates 4e, 4n-s, and 6a with Grignard reagents gives biaryls 9a-m, and the use of 2-halo and boron derivatives 4h, 4i, and 4k for Suzuki-Miyaura cross-coupling and generation of benzynes leads to naphthols 7a and 7b. A relative metalation ranking of the OSONEt(2)
Arylketones as Aryl Donors in Palladium-Catalyzed Suzuki–Miyaura Couplings
作者:Zhen-Yu Wang、Biao Ma、Hui Xu、Xing Wang、Xu Zhang、Hui-Xiong Dai
DOI:10.1021/acs.orglett.1c03048
日期:2021.11.5
Herein, we report the arylation, alkylation, and alkenylation of aryl ketones via a palladium-catalyzed Suzuki–Miyaura cross-coupling reaction. The use of the pyridine-oxazoline ligand is the key to the cleavage of the unstrained C–C bond. The late-stage arylation of aryl ketones derived from drugs and natural products demonstrated the synthetic utility of this protocol.
Decarboxylative Cross-Coupling of Aryl Tosylates with Aromatic Carboxylate Salts
作者:Lukas J. Gooßen、Nuria Rodríguez、Paul P. Lange、Christophe Linder
DOI:10.1002/anie.200905953
日期:2010.2.1
A bimetallic copper/palladium catalyst system is disclosed that enables the use of tosylates as carbon electrophiles in decarboxylative coupling reactions. A variety of aromaticcarboxylatesalts, regardless of their substitution pattern, have been coupled with these inexpensive and readily available electrophiles to give the corresponding biaryl compounds in good yields (see scheme).
Phosphine-Free Palladium(II)-Catalyzed Arylation of Naphthalene and Benzene with Aryl Iodides
作者:Chunxia Qin、Wenjun Lu
DOI:10.1021/jo801345b
日期:2008.9.19
A phosphine-free arylation of naphthalene and benzene with aryl iodides to give biaryls in moderate to good yields is carried out in the presence of catalytic Pd(OAc)2 and stoichiometric CF3CO2 Ag in TFE or/and TFA.
Aryl Grignard reagents were found to undergo coupling with aryl or alkenyl bromides in the presence of LiCl in a mixed solvent consisting of toluene and THF (2/1). Previously employed removal of THF with evacuation from Grignard solutions is no longer needed to obtain biaryls and styrene derivatives.