Convenient Processes for the Synthesis of Aromatic Ketones from Aryl Bromides and Carboxylic Anhydrides Using a Cobalt Catalysis
TL;DR: Results are disclosed that suggest the role played by cobalt species in the coupling of organozinc reagents with electrophiles could be similar to those of more commonplace transition metal complexes.
Abstract: The cross-coupling of various para- and meta-substituted aromatic bromides, mostly bearing sensitive moieties, with several carboxylic acid anhydrides is reported. This reaction can be carried out in two steps, by forming an aromatic organozinc reagent via cobalt catalysis in the first step, or even more interestingly in a single step, also by using a cobalt-based catalyst. The aromatic ketones are obtained by these new, mild, and convenient methods in 30-79% yields versus starting aryl bromide. Results are also disclosed that suggest the role played by cobalt species in the coupling of organozinc reagents with electrophiles could be similar to those of more commonplace transition metal complexes.
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TL;DR: Alkenylation of Acetylenic Grignard Reagents 1447 6.1.3.
Abstract: 3.1.2. From Vinylic Grignard Reagents 1437 3.1.3. From Aryl Halides and Alkenyl Acetates 1438 3.2. Aryl-Aryl Cross-coupling 1438 3.2.1. From Aromatic Organometallic Reagents 1438 3.2.2. From Two Aromatic Halides 1440 4. Csp2-Csp3 Cross-coupling Reactions 1440 4.1. Alkenylation 1440 4.1.1. From Aliphatic Organometallic Reagents 1440 4.1.2. From Aliphatic Halides 1442 4.2. Arylation 1442 4.2.1. From Aliphatic Halides 1442 4.2.2. From Aromatic Halides 1445 4.3. Allylation of Aromatic Organometallics 1446 5. Alkynylation 1446 5.1. Pioneering Works 1446 5.2. Benzylation of Acetylenic Grignard Reagents 1446 5.3. Alkylation of Acetylenic Grignard Reagents 1447 5.4. Alkenylation of Acetylenic Grignard Reagents 1447 6. Csp3-Csp3 Cross-coupling 1448 6.1. Allylation 1448 6.1.1. Allylation of Aliphatic Organozinc Compounds 1448
504 citations
TL;DR: The current state of the art of reductive cross-electrophile coupling is assessed and recent protocols with various combinations of alkyl, alkenyl, allyl, and aryl reagents are summarized and key mechanistic studies are highlighted.
Abstract: Reductive cross-electrophile coupling reactions have recently been developed to a versatile and sustainable synthetic tool for selective C-C bond formation. The employment of cheap and abundant electrophiles avoids the pre-formation and handling of organometallic reagents. In situ reductive coupling is effected in the presence of a transition-metal catalyst (Ni, Co, Pd, Fe) and a suitable metallic reductant (Mn, Zn, Mg). This Concept article assesses the current state of the art and summarizes recent protocols with various combinations of alkyl, alkenyl, allyl, and aryl reagents and highlights key mechanistic studies.
431 citations
TL;DR: The recent findings in metal-catalyzed reductive coupling reactions of aryl halides and (pseudo)halides with carbonyl-type compounds are summarized, with particular emphasis on the mechanistic interpretation of the results and future aspects of this area of expertise.
Abstract: Metal-catalyzed reductive coupling reactions of aryl halides and (pseudo)halides with carbonyl-type compounds have undergone an impressive development within the last years. These methodologies have shown to be a powerful alternate strategy, practicality aside, to the use of stoichiometric, well-defined, and, in some cases, air-sensitive organometallic species. In this Minireview, the recent findings in this field are summarized, with particular emphasis on the mechanistic interpretation of the results and future aspects of this area of expertise.
337 citations
TL;DR: Your contributions in this area for the preparation of a broad range of functionalized compounds from organometallic species or by direct cross-coupling are described.
229 citations
TL;DR: A practical and highly effective MgCl2-accelerated addition of various organozinc reagents to aldehydes and ketones as well as to CO2 under mild conditions is reported.
Abstract: The reactivity of functionalized arylzinc and benzylzinc reagents is significantly improved in the presence of MgCl2.
128 citations
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TL;DR: The Hammett equation has been widely used for the study and interpretation of organic reactions and their mechanisms as mentioned in this paper, and it is astonishing that u constants, obtained simply from the ionization of organic acids in solution, can frequently predict successfully equilibrium and rate constants for a variety of families of reactions in solution.
Abstract: The Hammett equation (and its extended forms) has been one of the most widely used means for the study and interpretation of organic reactions and their mechanisms. Although the Hammett methodology has been criticized by theoreticians because of its empirical foundation, it is astonishing that u constants, obtained simply from the ionization of organic acids in solution, can frequently predict successfully equilibrium and rate constants for a variety of families of reactions in solution. Almost every kind of organic reaction has been treated via the Hammett equation, or its extended form. The literature is so voluminous and extensive that there is no complete review of all that has been accomplished. Hammett's success in treating the electronic effect of substituents on the rates and equilibria of organic reactions1P2 led Taft to apply the same principles to steric and inductive and resonance effects? Then, more recently, octanol/ water partition coefficients (P) have been used for rationalizing the hydrophobic effects of organic compounds interacting with biological systems? The use of log P (for whole molecules) or n (for substituents), when combined with electronic and steric parameters, has opened up whole new regions of biochemical and pharmacological reactions to study by the techniques of physical organic chemistry.sf3 The combination of electronic, steric, hydrophobic, hydrophilic, and hydrogen-bonding7 parameters has been used to derive quantitative structure-activity relationships (QSAR) for a host of interactions of organic compounds with living systems or parts thereof. The binding of organic compounds to proteins,8 their interaction with enzymess and with cellsloJ1 and tiasues,12 their inhibition of organelles,l' and as antimalarial^'^
6,870 citations
TL;DR: The cross-coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond.
Abstract: The cross-coupling of organotin reagents with a variety of organic electrophiles, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. Because this mild, versatile reaction is tolerant of a wide variety of functional groups on either coupling partner, is stereospecific and regioselective, and gives high yields of product, it is ideal for use in the synthesis of elaborate organic molecules. When the coupling reaction is carried out in the presence of carbon monoxide, instead of a direct coupling, carbon monoxide insertion takes place, stitching the two coupling partners together and generating a ketone.
2,991 citations
TL;DR: In this article, a direct procedure for Arylboronic Esters was proposed for a cross-coupling reaction of Alkoxydiboron with Haloarenes.
Abstract: G e o r g T h i e m e V e r l a g K G , R ü d i g e r s t r a ß e 1 4 , 7 0 4 6 9 S t u t t g a r t , G e r m a n y 823 T . I S H I Y A M A , M . M U R A T A , N . M I Y A U R A * ( H O K K A I D O U N I V E R S I T Y , S A P P O R O , J A P A N ) Palladium(0)-Catalyzed Cross-Coupling Reaction of Alkoxydiboron with Haloarenes: A Direct Procedure for Arylboronic Esters J. Org. Chem. 1995, 60, 7508–7510.
1,355 citations
TL;DR: In this article, the crosscoupling reaction of (RO)2BB(OR)2 (RO =methoxo and pinacolato) with aryl triflates to give arylsboronates was carried out at 80 °C in the presence of PdCl2(dppf) (3 mol%), dppf(3 mol%) and KOAc (3 equivs) in dioxane.
323 citations
TL;DR: In this paper, the cross-coupling reaction of bis(pinacolato)diboron with chloroarenes to yield pinacol arylboronates was carried out in 1,4-dioxane at 80°C in the presence of KOAc (1.5 ǫ) and Pd(dba) 2 /2.4PCy 3 (3-6 mmol%).
254 citations