132682-77-0Relevant articles and documents
Nonsymmetrical Bis-Azine Biaryls from Chloroazines: A Strategy Using Phosphorus Ligand-Coupling
Boyle, Benjamin T.,Hilton, Michael C.,McNally, Andrew
supporting information, p. 15441 - 15449 (2019/11/02)
Distinct approaches to synthesize bis-azine biaryls are in demand as these compounds have multiple applications in the chemical sciences and are challenging targets for metal-catalyzed cross-coupling reactions. Most approaches focus on developing new reagents as the formal nucleophilic coupling partner that can function in metal-catalyzed processes. We present an alternative approach using pyridine and diazine phosphines as nucleophilic partners and chloroazines where the heterobiaryl bond is formed via a tandem SNAr-phosphorus ligand-coupling sequence. The heteroaryl phosphines are prepared from chloroazines and are bench-stable solids. A range of bis-azine biaryls can be formed from abundant chloroazines using this strategy that would be challenging using traditional approaches. A one-pot cross-electrophile coupling of two chloroazines is feasible, and we also compared the phosphorus-mediated strategy with metal-catalyzed coupling reactions to show advantages and compatibility.
General and selective copper-catalyzed reduction of tertiary and secondary phosphine oxides: Convenient synthesis of phosphines
Li, Yuehui,Das, Shoubhik,Zhou, Shaolin,Junge, Kathrin,Beller, Matthias
supporting information; experimental part, p. 9727 - 9732 (2012/07/14)
Novel catalytic reductions of tertiary and secondary phosphine oxides to phosphines have been developed. Using tetramethyldisiloxane (TMDS) as a mild reducing agent in the presence of copper complexes, PO bonds are selectively reduced in the presence of other reducible functional groups (FGs) such as ketones, esters, and olefins. Based on this transformation, an efficient one pot reduction/phosphination domino sequence allows for the synthesis of a variety of functionalized aromatic and aliphatic phosphines in good yields.
[NiCl2(dppp)]-catalyzed cross-coupling of aryl halides with dialkyl phosphite, diphenylphosphine oxide, and diphenylphosphine
Zhao, Yu-Long,Wu, Guo-Jie,Li, You,Gao, Lian-Xun,Han, Fu-She
supporting information; experimental part, p. 9622 - 9627 (2012/09/07)
We present a general approach to C-P bond formation through the cross-coupling of aryl halides with a dialkyl phosphite, diphenylphosphine oxide, and diphenylphosphane by using [NiCl2(dppp)] as catalyst (dppp=1,3-bis(diphenylphosphino)propane). This catalyst system displays a broad applicability that is capable of catalyzing the cross-coupling of aryl bromides, particularly a range of unreactive aryl chlorides, with various types of phosphorus substrates, such as a dialkyl phosphite, diphenylphosphine oxide, and diphenylphosphane. Consequently, the synthesis of valuable phosphonates, phosphine oxides, and phosphanes can be achieved with one catalyst system. Moreover, the reaction proceeds not only at a much lower temperature (100-120 °C) relative to the classic Arbuzov reaction (ca. 160-220 °C), but also without the need of external reductants and supporting ligands. In addition, owing to the relatively mild reaction conditions, a range of labile groups, such as ether, ester, ketone, and cyano groups, are tolerated. Finally, a brief mechanistic study revealed that by using [NiCl2(dppp)] as a catalyst, the NiII center could be readily reduced in situ to Ni0 by the phosphorus substrates due to the influence of the dppp ligand, thereby facilitating the oxidative addition of aryl halides to a Ni0 center. This step is the key to bringing the reaction into the catalytic cycle. Making bonds: C-P bonds were formed by the Ni-catalyzed cross-coupling of aryl halides and phosphorus substrates without the need of external reductants. Aryl bromides and less reactive aryl chlorides underwent smooth coupling with several different phosphorus substrates to afford phosphonates, phosphine oxides, and phosphines (see scheme; dppp=1,3-bis(diphenylphosphino)propane). Due to the mild reaction conditions, a range of labile groups, such as ether, ester, ketone, and cyano groups, are tolerated. Copyright
