Pincer-Nickel-Catalyzed Allyl-Aryl Coupling between Allyl Methyl Ethers and Arylzinc Chlorides
摘要:
The P,N,N-pincer nickel complex [Ni(C1l)-(N-(2-Ph2PC6H4)(2'-Me2NC6H4)}]-catalyzed allyl-aryl coupling was studied. The reaction of ally! methyl ethers, including (1-methoxyallyl)arenes and (3-methoxyprop-1-en-1-yl)arenes, with arylzinc chlorides afforded linear (E)-alkenes in high yields, whereas the reaction of (E)-1-methoxytridec-2-ene with p-Me2NC6H4ZnCl generated a mixture of linear and branched alkenes.
Nickel-Catalyzed Diaryl Ketone Synthesis by N–C Cleavage: Direct Negishi Cross-Coupling of Primary Amides by Site-Selective <i>N</i>,<i>N</i>-Di-Boc Activation
作者:Shicheng Shi、Michal Szostak
DOI:10.1021/acs.orglett.6b02952
日期:2016.11.18
the first amidecross-coupling by direct metal insertion of simple and readily available primary amides. The overall strategy by N,N-di-Boc activation/metal insertion is suitable for a broad range of coupling protocols via acylmetals. Mechanistic experiments suggest high reactivity of N,N-di-Boc activated 1° amides in direct amide C–N cross-couplings.
Transition-Metal-Free Cross-Coupling of Aryl and Heteroaryl Thiols with Arylzinc Reagents
作者:Bo Yang、Zhong-Xia Wang
DOI:10.1021/acs.orglett.7b03145
日期:2017.11.17
Cross-coupling of (hetero)arylthiols with arylzinc reagents via C–S cleavage was performed under transition-metal-free conditions. The reaction displays a wide scope of substrates and high functional-group tolerance. Electron-rich and -deficient (hetero)arylthiols and arylzinc reagents can be employed in this transformation. Mg2+ and Li+ ions were demonstrated to facilitate the reaction.
Mild Cobalt-Catalyzed Negishi Cross-Couplings of (Hetero)arylzinc Reagents with (Hetero)aryl Halides
作者:Diana Haas、Jeffrey M. Hammann、Ferdinand H. Lutter、Paul Knochel
DOI:10.1002/anie.201510665
日期:2016.3.7
CoCl2⋅2 LiCl (5 mol %) and HCO2Na (50 mol %) enables the cross‐coupling of various N‐heterocyclic chlorides and bromides as well as aromatic halogenated ketones with various electron‐rich and ‐poor arylzincreagents. The reactions reached full conversion within a few hours at 25 °C.
Reported herein is a palladium-catalyzed secondary benzylic imidoylative Negishi reaction leveraging the sterically bulky aromatic isocyanides as the imine source. This method allows the facile access of alkyl-, (hetero)aryl-, and alkynylzinc reagents to afford various α-substituted phenylacetone products under mild acidic hydrolysis, which are ubiquitous motifs in many pharmaceuticals and biologically
Directed Zincation or Magnesiation of the 2-Pyridone and 2,7-Naphthyridone Scaffold Using TMP Bases
作者:Dorothée S. Ziegler、Robert Greiner、Henning Lumpe、Laura Kqiku、Konstantin Karaghiosoff、Paul Knochel
DOI:10.1021/acs.orglett.7b02690
日期:2017.11.3
6-tetramethylpiperidyl) followed by trapping with electrophiles provided functionalized 2-pyridones and 2,7-naphthyridones. I/Mg exchange of iodinated 2-pyridone and 2,7-naphthyridone using i-PrMgCl·LiCl afforded magnesiated intermediates that reacted with electrophiles. A second magnesiation of the 2-pyridone scaffold was achieved by using TMPMgCl·LiCl. Additionally, we report CoCl2-catalyzed cross-couplings of