124215-44-7Relevant articles and documents
Synthesis of precursor imidazolium salts for the synthesis of N-heterocyclic carbines used as ligands for the enantioselective preparation of heterosteroids compounds
Guerri, Messaoud,Sekhri, Lakhdar,Olivier, Chuzel,Jean-Luc, Parrain
, p. 427 - 434 (2014)
The imidazolium salts 1-phenyl-3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)-1H-imidazol-3-ium bromide (4), and 1-(pyrimidin-2-yl)-3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan- 2-yl)propyl)-1H-imidazol-3-ium bromide (5) were respectively prepa
Scalable, Durable, and Recyclable Metal-Free Catalysts for Highly Efficient Conversion of CO2 to Cyclic Carbonates
Li, Bo,Wu, Guang-Peng,Xie, Rui,Yang, Guan-Wen,Yang, Li,Zhang, Yao-Yao
, p. 23291 - 23298 (2020)
A series of highly active organoboron catalysts for the coupling of CO2 and epoxides with the advantages of scalable preparation, thermostability, and recyclability is reported. The metal-free catalysts show high reactivity towards a wide scope of cyclic carbonates (14 examples) and can withstand a high temperature up to 150 °C. Compared with the current metal-free catalytic systems that use mol % catalyst loading, the catalytic capacity of the catalyst described herein can be enhanced by three orders of magnitude (epoxide/cat.=200 000/1, mole ratio) in the presence of a cocatalyst. This feature greatly narrows the gap between metal-free catalysts and state-of-the-art metallic systems. An intramolecular cooperative mechanism is proposed and certified on the basis of investigations on crystal structures, structure–performance relationships, kinetic studies, and key reaction intermediates.
Synthesis and structure of Ag(i), Pd(ii), Rh(i), Ru(ii) and Au(i) NHC-complexes with a pendant Lewis acidic boronic ester moiety
Toure, Momar,Chuzel, Olivier,Parrain, Jean-Luc
, p. 7139 - 7143 (2015)
Bifunctional Ag(i), Pd(ii), Rh(i), Ru(ii) and Au(i) complexes containing a NHC ligand and a pendant trivalent boron moiety have been synthesized in high yields. Fine-tuned reaction conditions were used to prevent potential ligand self-quenching or polymer
Hydroboration of unsaturated phosphonic esters: Synthesis of boronophosphonates and trisubstituted vinylphosphonates
Pergament, Inna,Srebnik, Morris
, p. 217 - 219 (2001)
equation presented Hydroboration of vinyl phosphonates with pinacolborane (PBH) proceeds to give phosphonoboronates, 2. Surprisingly, such compounds have not been reported before. The reaction works well with terminal alkenylphosphonates. Internal alkenylphosphonates give complex mixtures. Hydroboration/Suzuki coupling of alkynylphosphonates, with PBH, in a one-pot procedure gives trisubstituted vinylphosphonates in good overall yields and provides a new synthesis of these compounds.
Umpolung of B?H Bonds by Metal–Ligand Cooperation with Cyclopentadienone Iridium Complexes
Higashi, Takuya,Kusumoto, Shuhei,Nozaki, Kyoko
, p. 2844 - 2848 (2021)
In contrast to conventional metal–ligand cooperative cleavage of a B?H bond, which provides a B cation on the ligand and an H anion on the metal, we report herein the umpolung of B?H bonds by novel cyclopentadienone iridium complexes. The B?H bonds of 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (HBpin) and 1,8-naphthalenediaminatoborane (HBdan) were cleaved to give a B anion on the metal and an H cation on the phenolic oxygen atom of the ligand. Mechanistic investigation by DFT calculations revealed that the alkoxycarbonyl-substituted cyclopentadienone ligand facilitated deprotonation from Ir?H after oxidative addition of the B?H bond to give the umpolung product. The generated boryliridium complex was found to undergo borylation of an allyl halide in the presence of base, thus showing the nucleophilic nature of the boron atom.
Synthesis of chiral branched allylamines through dual photoredox/nickel catalysis
Garbacz, Mateusz,Stecko, Sebastian
supporting information, p. 8578 - 8585 (2021/10/20)
Allylamines are versatile building blocks in the synthesis of various naturally occurring products and pharmaceuticals. In contrast to terminal allylamines, the methods of synthesis of their branched congeners with internal, stereodefined double bonds are less explored. This work describes a new approach for the preparation of allylaminesviacross-coupling of alkyl bromides with simple 3-bromoallylamines by merging the photoredox approach and Ni catalysis. The reaction proceeds under mild conditions, under blue light irradiation, and in the presence of an organic dye, 4CzIPN, as a photocatalyst. The scope of suitable reaction partners is broad, including alkyl bromides bearing reactive functionalities (e.g., esters, nitriles, aldehydes, ketones, epoxides) andN-protected allylamines, as well asN-allylated secondary and tertiary amines and heterocycles. The employment of non-racemic starting materials allows for rapid and easy construction of complex multifunctional allylamine derivatives without the loss of enantiomeric purity.
The Synthesis of Chiral Allyl Carbamates via Merger of Photoredox and Nickel Catalysis
Garbacz, Mateusz,Stecko, Sebastian
supporting information, p. 3213 - 3222 (2020/07/06)
A mild, and versatile, organophotoredox/Ni-mediated protocol was developed for the direct preparation of diverse, enantioenriched allyl carbamates. The reported approach represents a significant departure from classical step-by-step synthesis of allyl carbamates. This dual photoredox/Ni based strategy offers unrivalled capacity for convergent unification of readily available alkyl halides and chiral carbamates derived from 1-bromo-alken-3-ols with high chemoselectivity and efficiency. The reported photoredox/Ni catalyzed cross-coupling reaction is not limited to carbamates, but also to other O-derivatives such as esters, ethers, acetals, carbonates or silyl ethers. To demonstrate the utility of the reported protocol, the resulting allyl carbamates were transformed into functionalized non-racemic allylamines through a sigmatropic rearrangement reaction in enantiospecific manner. This approach allowed for synthesis of enantiomeric allylamines by a simple control of the geometry of a double bond of allyl carbamates. (Figure presented.).
Lithium compounds as single site catalysts for hydroboration of alkenes and alkynes
Bisai, Milan Kumar,Yadav, Sandeep,Das, Tamal,Vanka, Kumar,Sen, Sakya S.
supporting information, p. 11711 - 11714 (2019/10/02)
The hydroboration of alkenes and alkynes using easily accessible lithium compounds [2,6-di-tert-butyl phenolatelithium (1a) and 1,1′ dilithioferrocene (1b)] has been achieved with good yields, high functional group tolerance and excellent chemoselectivity
Aluminum-Catalyzed Hydroboration of Alkenes
Bismuto, Alessandro,Cowley, Michael J.,Thomas, Stephen P.
, p. 2001 - 2005 (2018/03/13)
The aluminum-catalyzed hydroboration of alkenes with HBpin is reported using simple commercially available aluminum hydride precatalysts [LiAlH4 or sodium bis(2-methoxyethoxy)aluminum hydride (Red-Al)]. Good substrate scope and functional group
Potassium haloalkyltrifluoroborate salts: Synthesis, application, and reversible ligand replacement with MIDA
Burke, Sarah J.,Gamrat, James M.,Santhouse, Jacqueline R.,Tomares, Dylan T.,Tomsho, John W.
, p. 5500 - 5503 (2015/09/21)
Increased interest in boron-containing pharmaceuticals has created a need for efficient syntheses of organoboron compounds. This article describes one- and two-pot syntheses of potassium haloalkyltrifluoroborate salts, important building blocks for the incorporation of boron into complex molecules. The sequential, high-yielding procedures (65% to 92%) involve hydroboration of commercially available haloalkenes with dichloroborane (prepared in situ from triethylsilane and boron trichloride), followed by treatment of the crude hydroboration products with potassium hydrogen difluoride. A hexaethyldisiloxane byproduct that hinders the isolation of the desired boronic acids and esters was identified and easily removed via this procedure. The value of the potassium haloalkyltrifluoroborate salts is subsequently demonstrated in example substitution reactions, which were followed by a reversible ligand replacement with N-methyliminodiacetic acid (MIDA). Reversibly switching these orthogonal boron protecting groups enables full exploitation of their favorable chemical properties, effectively bridging these platforms and further expanding their scope and utility.
