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1.
Fu-Peng Wu Yang Yuan Claas Schünemann Prof. Dr. Paul C. J. Kamer Prof. Dr. Xiao-Feng Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10537-10541
The borocarbonylative coupling of unactivated alkenes with alkyl halides remains a challenge. In this communication, a Cu-catalyzed borocarbonylative coupling of unactivated alkenes with alkyl halides for the synthesis of β-boryl ketones has been developed. A broad range of β-boryl ketone derivatives was prepared in moderate to excellent yields with complete regioselectivity. 相似文献
2.
Fu‐Peng Wu Yang Yuan Claas Schünemann Paul C. J. Kamer Xiao‐Feng Wu 《Angewandte Chemie (International ed. in English)》2020,59(26):10451-10455
The borocarbonylative coupling of unactivated alkenes with alkyl halides remains a challenge. In this communication, a Cu‐catalyzed borocarbonylative coupling of unactivated alkenes with alkyl halides for the synthesis of β‐boryl ketones has been developed. A broad range of β‐boryl ketone derivatives was prepared in moderate to excellent yields with complete regioselectivity. 相似文献
3.
Nickel‐Catalyzed Cross‐Electrophile Coupling with Organic Reductants in Non‐Amide Solvents
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Dr. Lukiana L. Anka‐Lufford Kierra M. M. Huihui Dr. Nicholas J. Gower Dr. Laura K. G. Ackerman Prof. Dr. Daniel J. Weix 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11564-11567
Cross‐electrophile coupling of aryl halides with alkyl halides has thus far been primarily conducted with stoichiometric metallic reductants in amide solvents. This report demonstrates that the use of tetrakis(dimethylamino)ethylene (TDAE) as an organic reductant enables the use of non‐amide solvents, such as acetonitrile or propylene oxide, for the coupling of benzyl chlorides and alkyl iodides with aryl halides. Furthermore, these conditions work for several electron‐poor heterocycles that are easily reduced by manganese. Finally, we demonstrate that TDAE addition can be used as a control element to ‘hold’ a reaction without diminishing yield or catalyst activity. 相似文献
4.
Alkyloxy porphyrins have been prepared by direct coupling of 5-para-hydroxyphenyl-10,15,20-triphenylporphyrin and alkyl halides under microwave irradiation within several minutes. The length of the alkyl halides has no obvious effect on the yields and reaction time; however, the steric structure of the alkyl halides has a great impact on the reaction time. All the products were confirmed by 1H NMR. 相似文献
5.
Laura K. G. Ackerman Lukiana L. Anka-Lufford Marina Naodovic Daniel J. Weix 《Chemical science》2015,6(2):1115-1119
The nickel-catalyzed cross-coupling of aryl halides with alkyl radicals derived from alkyl halides has recently been extended to couplings with carbon radicals generated by a co-catalyst. In this study, a new co-catalyst, cobalt phthalocyanine (Co(Pc)), is introduced and demonstrated to be effective for coupling substrates not prone to homolysis. This is because Co(Pc) reacts with electrophiles by an SN2 mechanism instead of by the electron-transfer or halogen abstraction mechanisms previously explored. Studies demonstrating the orthogonal reactivity of (bpy)Ni and Co(Pc), applying this selectivity to the coupling of benzyl mesylates with aryl halides, and the adaptation of these conditions to the less reactive benzyl phosphate ester and an enantioconvergent reaction are presented. 相似文献
6.
Ohmiya H Tsuji T Yorimitsu H Oshima K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(22):5640-5648
Details of cobalt-catalyzed cross-coupling reactions of alkyl halides with allylic Grignard reagents are disclosed. A combination of cobalt(II) chloride and 1,2-bis(diphenylphosphino)ethane (DPPE) or 1,3-bis(diphenylphosphino)propane (DPPP) is suitable as a precatalyst and allows secondary and tertiary alkyl halides--as well as primary ones--to be employed as coupling partners for allyl Grignard reagents. The reaction offers a facile synthesis of quaternary carbon centers, which has practically never been possible with palladium, nickel, and copper catalysts. Benzyl, methallyl, and crotyl Grignard reagents can all couple with alkyl halides. The benzylation definitely requires DPPE or DPPP as a ligand. The reaction mechanism should include the generation of an alkyl radical from the parent alkyl halide. The mechanism can be interpreted in terms of a tandem radical cyclization/cross-coupling reaction. In addition, serendipitous tandem radical cyclization/cyclopropanation/carbonyl allylation of 5-alkoxy-6-halo-4-oxa-1-hexene derivatives is also described. The intermediacy of a carbon-centered radical results in the loss of the original stereochemistry of the parent alkyl halides, creating the potential for asymmetric cross-coupling of racemic alkyl halides. 相似文献
7.
Dr. Anna Hedström Dr. Zakieh Izakian Irma Vreto Dr. Carl‐Johan Wallentin Prof. Dr. Per‐Ola Norrby 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(15):5946-5953
The radical nature of iron‐catalyzed cross‐coupling between Grignard reagents and alkyl halides has been studied by using a combination of competitive kinetic experiments and DFT calculations. In contrast to the corresponding coupling with aryl halides, which commences through a classical two‐electron oxidative addition/reductive elimination sequence, the presented data suggest that alkyl halides react through an atom‐transfer‐initiated radical pathway. Furthermore, a general iodine‐based quenching methodology was developed to enable the determination of highly accurate concentrations of Grignard reagents, a capability that facilitates and increases the information output of kinetic investigations based on these substrates. 相似文献
8.
Treatment of alkyl halides, including tertiary alkyl bromides, with benzylic or allylic Grignard reagent in the presence of a catalytic amount of silver nitrate in ether yielded the corresponding cross-coupling products in high yields. The coupling reactions of tertiary alkyl halides provide efficient access to quaternary carbon centers. 相似文献
9.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(12):3367-3371
Suzuki, Negishi, and Kumada couplings are some of the most important reactions for the formation of skeletal C−C linkages. Their widespread use to forge bonds between two aromatic rings has enabled every branch of chemical science. The analogous union between alkyl halides and metallated aryl systems has not been as widely employed due to the lack of commercially available halide building blocks. Redox‐active esters have recently emerged as useful surrogates for alkyl halides in cross‐coupling chemistry. Such esters are easily accessible through reactions between ubiquitous carboxylic acids and coupling agents widely used in amide bond formation. This article features an amalgamation of in‐house experience bolstered by approximately 200 systematically designed experiments to accelerate the selection of ideal reaction conditions and activating agents for the cross‐coupling of primary, secondary, and tertiary alkyl carboxylic acids with both aryl and heteroaryl organometallic species. 相似文献
10.
Zinc‐Catalyzed Borylation of Primary,Secondary and Tertiary Alkyl Halides with Alkoxy Diboron Reagents at Room Temperature
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Dr. Shubhankar Kumar Bose Dr. Katharina Fucke Prof. Dr. Lei Liu Prof. Dr. Patrick G. Steel Prof. Dr. Todd B. Marder 《Angewandte Chemie (International ed. in English)》2014,53(7):1799-1803
A new catalytic system based on a ZnII NHC precursor has been developed for the cross‐coupling reaction of alkyl halides with diboron reagents, which represents a novel use of a Group XII catalyst for C? X borylation. This approach gives borylations of unactivated primary, secondary, and tertiary alkyl halides at room temperature to furnish alkyl boronates, with good functional‐group compatibility, under mild conditions. Preliminary mechanistic investigations demonstrated that this borylation reaction seems to involve one‐electron processes. 相似文献
11.
Iain A.S. Walters 《Tetrahedron letters》2006,47(3):341-344
A simple Ni-catalysed cross-coupling protocol for amino-heteroaryl chlorides with alkylzinc reagents has been developed. The alkylzinc reagents can be commercially available dialkylzincs or alkylzinc halides, or can be conveniently generated in situ from diethylzinc and primary alkyl bromides in the presence of the same inexpensive Ni catalyst used to effect the subsequent coupling reaction. 相似文献
12.
Computational Insight into Nickel‐Catalyzed Carbon–Carbon versus Carbon–Boron Coupling Reactions of Primary,Secondary, and Tertiary Alkyl Bromides
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Dr. Man Sing Cheung Fu Kit Sheong Prof. Dr. Todd B. Marder Prof. Dr. Zhenyang Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(20):7480-7488
The nickel‐catalyzed alkyl–alkyl cross‐coupling (C?C bond formation) and borylation (C?B bond formation) of unactivated alkyl halides reported in the literature show completely opposite reactivity orders in the reactions of primary, secondary, and tertiary alkyl bromides. The proposed NiI/NiIII catalytic cycles for these two types of bond‐formation reactions were studied computationally by means of DFT calculations at the B3LYP level. These calculations indicate that the rate‐determining step for alkyl–alkyl cross‐coupling is the reductive elimination step, whereas for borylation the rate is determined mainly by the atom‐transfer step. In borylation reactions, the boryl ligand involved has an empty p orbital, which strongly facilitates the reductive elimination step. The inability of unactivated tertiary alkyl halides to undergo alkyl–alkyl cross‐coupling is mainly due to the moderately high reductive elimination barrier. 相似文献
13.
A Ni-catalyzed reductive approach to the cross-coupling of two unactivated alkyl halides has been successfully developed. The reaction works efficiently for primary and secondary halides, with at least one being bromide. The mild reaction conditions allow for excellent functional group tolerance and provide the C(sp(3))-C(sp(3)) coupling products in moderate to excellent yields. 相似文献
14.
Conclusions An efficient method has been developed for the synthesis of 1,4-enynes, conjugated acetylenes and aryl acetylenes by the cross coupling of magnesium diacetylenides with allyl ethers and esters, alkyl halides, allyl halides, aryl halides, allyl sulfides, and allylsulfones, using Ni and Pd complexes as the catalyst.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 429–433, February, 1936. 相似文献
15.
Özgen Ömür PekelEnder Erdik 《Tetrahedron letters》2011,52(52):7087-7090
A nickel-catalyzed process for the cross-coupling of mixed arylzincs and primary alkyl halides has been developed. The reaction of a methylarylzinc with a primary alkyl halide in THF in the presence of NiCl2/PPh3 takes place with selective aryl transfer at room temperature in moderate yields. This protocol provides an atom-economic alternative to aryl-primary alkyl coupling using diarylzincs. 相似文献
16.
A mild, functional group tolerant palladium-catalyzed Negishi coupling of pyrazole triflates and nonaflates with alkyl, benzyl, and aryl zinc halides has been developed. It allows quick access to 3-substituted pyrazole analogs at late stage via common synthetic intermediates. 相似文献
17.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(42):13283-13286
The construction of all C(sp3) quaternary centers has been successfully achieved under Ni‐catalyzed cross‐electrophile coupling of allylic carbonates with unactivated tertiary alkyl halides. For allylic carbonates bearing C1 or C3 substituents, the reaction affords excellent regioselectivity through the addition of alkyl groups to the unsubstituted allylic carbon terminus. The allylic alkylation method also exhibits excellent functional‐group compatibility, and delivers the products with high E selectivity. 相似文献
18.
Anderson KW Ikawa T Tundel RE Buchwald SL 《Journal of the American Chemical Society》2006,128(33):10694-10695
The direct and selective synthesis of phenols from aryl/heteroaryl halides and KOH has been achieved through the use of highly active monophosphine-based catalysts derived from Pd(2)dba(3) and ligands L1 or L2 and the biphasic solvent system 1,4-dioxane/H(2)O. We have also demonstrated a one-pot method of phenol formation/alkylation for the preparation of alkyl aryl ethers from aryl halides. In many instances, this protocol overcomes limitations in existing Pd-catalyzed coupling reactions of aliphatic alcohols with aryl halides. Finally, we demonstrate that substituted benzofurans can be prepared efficiently via a Pd-catalyzed phenol formation/cyclization protocol starting from 2-chloroaryl alkynes. 相似文献
19.
Ren P Vechorkin O von Allmen K Scopelliti R Hu X 《Journal of the American Chemical Society》2011,133(18):7084-7095
A structure-activity study was carried out for Ni catalyzed alkyl-alkyl Kumada-type cross coupling reactions. A series of new nickel(II) complexes including those with tridentate pincer bis(amino)amide ligands ((R)N(2)N) and those with bidentate mixed amino-amide ligands ((R)NN) were synthesized and structurally characterized. The coordination geometries of these complexes range from square planar, tetrahedral, to square pyramidal. The complexes had been examined as precatalysts for cross coupling of nonactivated alkyl halides, particularly secondary alkyl iodides, with alkyl Grignard reagents. Comparison was made to the results obtained with the previously reported Ni pincer complex [((Me)N(2)N)NiCl]. A transmetalation site in the precatalysts is necessary for the catalysis. The coordination geometries and spin-states of the precatalysts have a small or no influence. The work led to the discovery of several well-defined Ni catalysts that are significantly more active and efficient than the pincer complex [((Me)N(2)N)NiCl] for the coupling of secondary alkyl halides. The best two catalysts are [((H)NN)Ni(PPh(3))Cl] and [((H)NN)Ni(2,4-lutidine)Cl]. The improved activity and efficiency was attributed to the fact that phosphine and lutidine ligands in these complexes can dissociate from the Ni center during catalysis. The activation of alkyl halides was shown to proceed via a radical mechanism. 相似文献
20.
Chang Liu Zengyu Zhang Liang-Liang Zhao Prof. Guy Bertrand Prof. Xiaoyu Yan 《Angewandte Chemie (International ed. in English)》2023,62(24):e202303478
Ketones are among the most useful functional groups in organic synthesis, and they are commonly encountered in a broad range of compounds with various applications. Herein, we describe the mesoionic carbene-catalyzed coupling reaction of aldehydes with non-activated secondary and even primary alkyl halides. This metal-free method utilizes deprotonated Breslow intermediates derived from mesoionic carbenes (MICs), which act as super electron donors and induce the single-electron reduction of alkyl halides. This mild coupling reaction has a broad substrate scope and tolerates many functional groups, which allows to prepare a diversity of simple ketones as well as bio-active molecules by late-stage functionalization. 相似文献