Showing papers on "Grignard reaction published in 2022"
TL;DR: The first visible-light-induced cobalt-catalyzed asymmetric reductive Grignard-type addition for chiral benzyl alcohols was reported in this article .
Abstract: Grignard addition is one of the most important methods used for syntheses of alcohol compounds and has been known for over a hundred years. However, research on asymmetric catalysis relies on the use of organometallic nucleophiles. Here, we report the first visible-light-induced cobalt-catalyzed asymmetric reductive Grignard-type addition for synthesizing chiral benzyl alcohols (>50 examples, up to 99% yield, and 99% ee). This methodology has the advantages of mild reaction conditions, good functionality tolerance, excellent enantiocontrol, the avoidance of mass metal wastes, and the use of precious metal catalysts. Kinetic realization studies suggested that migratory insertion of an aryl cobalt species into the aldehyde was the rate-determining step of the reductive addition reaction.
30 citations
TL;DR: The preparation of enantioenriched sulfonimidoyl fluorides and their stereospecific reaction at sulfur with Grignard reagents is reported, including methyl.
14 citations
15 Mar 2022
TL;DR: In this paper , the safety aspects of the mechanochemical Grignard reaction are pointed out so that appropriate risk management plans can be devised to ensure its safe use, and the results of the reaction were reported for a broad range of substrates even when the reaction was performed under the ambient atmosphere, making the process highly appealing to a wide synthetic community.
Abstract: The Grignard reaction has been one of the most versatile workhorses for synthetic organic chemists for more than a century. Typically, the preparation of Grignard reagents and their subsequent reactions require anhydrous solvents and a protective inert atmosphere. A recent report showed that the reactions could be performed under mechanochemical conditions by ball-milling magnesium metal, an organic halide, and a small amount of an ethereal solvent together followed by the addition of an electrophile. Excellent results were reported for a broad range of substrates even when the reaction was performed under the ambient atmosphere, making the process highly appealing to a wide synthetic community. In this commentary, some safety aspects of this mechanochemical Grignard reaction are pointed out so that appropriate risk management plans can be devised to ensure its safe use.
4 citations
TL;DR: In this paper , the Barbier reaction of cinnamaldehyde was shown to yield a macromolecule with interesting aggregation-induced emission type non-conjugated luminescence properties.
3 citations
TL;DR: In this paper , the thermal hazard assessment of cyclohexane-type liquid crystal monomers (CLCMs) from the Grignard cross-coupling reaction is presented.
1 citations
TL;DR: In this article , the thermophysical properties of the resulting compounds are studied and the effect of the structure of the highly branched polymer and the nature of its terminal groups on the formation of a carbon residue (pyrolysate) is evaluated.
Abstract: The Grignard reaction of (chloroalkyl)chlorosilanes affords a series of highly branched polycarbosilanes featuring two types of terminal groups. The thermophysical properties of the resulting compounds are studied. The effect of the structure of the highly branched polymer and the nature of its terminal groups on the formation of a carbon residue (pyrolysate) is evaluated. The potential of application of poly(chloromethyl)-trichlorosilane with terminal SiH groups as a precursor for SiC ceramics is demonstrated.
1 citations
TL;DR: In this article , an example of Grignard reagents acting as halide nucleophiles to form alkyl iodides and bromides was reported. But this was performed in a one-pot reaction starting from alcohols, which proceed through mesylate intermediates.
Abstract: Grignard reagents are commonly used as carbanion equivalents. Herein, we report an example of Grignard reagents acting as halide nucleophiles to form alkyl iodides and bromides. We establish that Grignard reagents can convert alkyl mesylates into alkyl halides, as well as be employed in a one-pot halogenation reaction starting from alcohols, which proceed through mesylate intermediates. The halogenation reaction is confirmed to occur by an SN2 pathway with inversion of configuration and is demonstrated to be efficient on multi-gram scale.
1 citations
TL;DR: The synthesis of the 16-membered polyhydroxylated macrolide, Aspergillide D has been accomplished using the Grignard reaction, Sharpless asymmetric epoxidation Regioselective ring opening of epoxy alcohol, Wittig olefination and Yamaguchi macrolactonisation as key steps as mentioned in this paper .
TL;DR: In this paper , the first example of Grignard-type nucleophilic addition of C(sp2)-H bonds to unactivated aldehydes catalyzed by high-oxidation-state ruthenium(II) was reported.
Abstract: The Grignard-type nucleophilic addition of C(sp2)-H bonds to aldehydes catalyzed by high-oxidation-state transition metal complexes is limited to activated aldehydes. Herein, we report the first example of Grignard-type nucleophilic addition of C(sp2)-H bonds to unactivated aldehydes catalyzed by high-oxidation-state ruthenium(II). The reaction has mild reaction conditions and good functional group tolerance. The corresponding alcohol products are obtained in good to excellent yields.
TL;DR: The first total synthesis of penicyclone A, a novel deep-sea fungus-derived polyketide, and a reevaluation of its antimicrobial activity was described in this paper .
Abstract: We describe the first total synthesis of penicyclone A, a novel deep-sea fungus-derived polyketide, and a reevaluation of its antimicrobial activity. The synthesis of this unique spirolactone was achieved in 10 steps starting from a known d-ribose derivative. The key steps include a double Grignard reaction for the diastereoselective construction of the chiral tertiary alcohol intermediate, tandem oxidation/cyclization, and photooxygenation, followed by an oxidative rearrangement to introduce the enone functionality.