2728-04-3Relevant articles and documents
Pd-Catalyst Containing a Hemilabile P,C-Hybrid Ligand in Amino Dicarbonylation of Aryl Halides for Synthesis of α-Ketoamides
Yang, Shu-Qing,Yao, Yin-Qing,Chen, Xiao-Chao,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
, p. 1032 - 1041 (2021/05/07)
The amino dicarbonylation of aryl halides affording α-ketoamides with Pd catalysts is highly dependent on the stereoelectronic properties of the involved ligands. Ionic diphosphine ligand L4 can serve as precursor of a hemilabile P,C (phosphine, carbene)-hybrid ligand to form a stable Pd(II)-complex, Pd-L4. In contrast, analogues L1-L3 with a similar 1-(thiophen-3-yl)-benzimidazolyl skeleton behave as typical (mono/di)phosphines. The catalytic system resulting from the complexation of PdCl2(MeCN)2 and L4 exhibits good catalytic performance in terms of aryl iodides conversion (81-95%) and α-ketoamide selectivity (80-91%), as well as the available recyclability in the RTIL of [Bpy]BF4. The in situ FT-IR analysis reveals that the PdCl2(MeCN)2-L4 catalytic system favors the amino dicarbonylation toward α-ketoamides according to the proposed mechanism of cycle I, which involves two independent CO-insertion steps.
α-C-H/N-H Annulation of Alicyclic Amines via Transient Imines: Preparation of Polycyclic Lactams
Chen, Weijie,Seidel, Daniel
supporting information, p. 3729 - 3734 (2021/05/31)
Polycyclic lactams are prepared in a single operation from o-toluamides and cyclic amines in a process that involves transient cyclic imines, species that are conveniently obtained in situ from the corresponding lithium amides and simple ketone oxidants. Imines thus generated, such as 1-pyrroline and 1-piperideine, engage lithiated o-toluamides in a facile annulation process. Undesired side reactions such as imine deprotonation and o-toluamide dimerization are suppressed through the judicious choice of reaction conditions.
Pd-Catalyzed Oxidative Aminocarbonylation of Arylboronic Acids with Unreactive Tertiary Amines via C-N Bond Activation
Kolekar, Yuvraj A.,Bhanage, Bhalchandra M.
, p. 14028 - 14035 (2021/05/29)
An efficient synthesis of tertiary amides from aryl boronic acids and inert tertiary amines through the oxidative carbonylation via C(sp3)-N bond activation is presented. This protocol significantly restricts the homocoupling biarylketone product. It involves the use of a homogeneous PdCl2/CuI catalyst and a heterogeneous Pd/C based catalyst, which promotes C(sp3)-N bond activation of tertiary amines with aryl boronic acids. This process represents a ligand-free, base-free, and recyclable catalyst along with an ideal oxidant like molecular oxygen.
Supramolecular Pd(II) complex of DPPF and dithiolate: An efficient catalyst for amino and phenoxycarbonylation using Co2(CO)8 as sustainable C1 source
Gaikwad, Vinayak V.,Mane, Pravin A.,Dey, Sandip,Patel, Divya,Bhanage, Bhalchandra M.
, (2019/11/28)
Highly active, efficient and robust “dppf ligated tetranuclear palladium dithiolate complex” was synthesized and applied as a catalyst for chemical fixation of carbon monoxide for the synthesis value added chemicals such as tertiary amide and aromatic esters. The synthesized catalyst was characterized using different analytical techniques such as elemental analysis, 1H and 31P NMR spectroscopy. The use of Co2(CO)8 as a cheap, less toxic and low melting solid surrogate are additional advantages over the current protocol. The catalyst showed superior activity towards the Amino (10?3 mol % catalyst) and Phenoxycarbonylation (10-2 mol % catalyst) and high TON (104 to 103) and TOF (103 to 102 h-1). The Betol and Lintrin (active drug molecules) were synthesized under an optimized reaction condition. The scalability of the current protocol has been demonstrated up-to the gram level.
SOLVENTS FOR ORGANOMETALLIC REAGENTS
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Paragraph 0039; 0040, (2020/02/23)
In an embodiment, the present disclosure pertains to a solvent including a hydrocarbon oligomer with at least 20 carbon atoms, where the hydrocarbon oligomer has at least one of a low viscosity, a low vapor pressure, and a high flashpoint. In another embodiment, the present disclosure pertains to a solution including a poly(α-olefin) and a reactive organometallic reagent. In a further embodiment, the present disclosure pertains to a solution including an oligomeric hydrocarbon and a reactive organometallic reagent. In an additional embodiment, the present disclosure pertains to a method for creating a solution, where the method includes adding a reactive organometallic reagent to an oligomeric hydrocarbon.
Palladium-Catalyzed N-Acylation of Tertiary Amines by Carboxylic Acids: A Method for the Synthesis of Amides
Li, Zhaohui,Liu, Long,Xu, Kaiqiang,Huang, Tianzeng,Li, Xinyi,Song, Bin,Chen, Tieqiao
supporting information, p. 5517 - 5521 (2020/07/14)
A palladium-catalyzed N-acylation of tertiary amines by carboxylic acids was achieved through C-N cleavage. This reaction showed a wide substrate scope. Both aromatic and aliphatic acids served well as the acylating reagents and coupled with tertiary amines to produce the corresponding amides in good to excellent yields. With the strategy, bioactive carboxylic acids were also efficiently modified, highlighting the synthetic value of the process in organic synthesis.
Asymmetric synthesis of 2,3-dimethoxy-8-oxoberbine, precursor of 0-methylbharatamine
Chrzanowska, Maria,Dreas, Agnieszka,Meissner, Zofia
, p. 1073 - 1085 (2019/08/01)
The enantiospecific and enantioselective syntheses of 2,3-dimethoxy-8-oxoberbine were performed using the lateral retaliation methodology. In the enantiospecific synthesis (4S)-2,2,4-trimethyl-3-(o-toluoyl)-oxazolidine incorporating (S)-alaninol as the ch
Nickel-catalyzed reductive defunctionalization of esters in the absence of an external reductant: Activation of C-O bonds
Iyori, Yasuaki,Takahashi, Kenjiro,Yamazaki, Ken,Ano, Yusuke,Chatani, Naoto
supporting information, p. 13610 - 13613 (2019/11/14)
The nickel-catalyzed reductive cleavage of esters in the absence of an external reductant, which involves the cleavage of an inert acyl C-O bond in O-Alkyl esters is reported. Various groups, such as N-containing heterocycles, esters, amides, and even arene rings can function as a directing group.
Safer solvents for reactive organometallic reagents
Malinski, Thomas J.,Bergbreiter, David E.
supporting information, p. 3926 - 3929 (2018/10/02)
This paper describes the use of poly(α -olefin)s (PAOs) as safer alternatives to cyclohexane, hexanes, and heptane as solvents for alkyllithium reagents. While PAOs like any alkane are flammable, PAOs do not readily catch on fire because they contain 20 or more carbon atoms, a low volatility, and have a high flash point vis-à-vis alkanes like hexane. Also unlike conventional alkanes, PAOs can be quantitatively separated from polar organic solvents and polar organic products either by a simple gravity separation or by an extraction after a reaction. Any leaching of the PAO solvent into a polar phase during such a separation can be minimized by addition of small amounts of water to the polar phase. However, while these PAO solvents have some physical differences from conventional low molecular weight volatile alkanes, they otherwise behave like alkanes and alkyllithium reagents in these PAO solvents can used in their conventional reactions in these PAO solvents.
Restricted amide rotation with steric hindrance induced multiple conformations
Krishnan,Vazquez, Salvador,Maitra, Kalyani,Maitra, Santanu
, p. 148 - 151 (2017/10/23)
The C–N bond character is dependent directly upon the resonance-contributor structure population driven by the delocalized nitrogen lone-pair of electrons. In the case of N, N-dibenzyl-ortho-toluamide (o-DBET), the molecule adopts subpopulations of confor
