Presence Of TMSCl Research Articles

TMSCl-Promoted Sulfonylation of Propargylic Alcohols with Sodium Sulfinates for the Construction of (E)-1,3-Disulfonylpropenes and (E)-1-Sulfonylpropenols.

A direct and novel transformation of propargylic alcohols with sodium sulfinates for the regio- and stereoselective synthesis of (E)-1,3-disulfonylpropenes and (E)-1-sulfonylpropenols was successfully developed in the presence of TMSCl under mild conditions. The preliminary mechanistic experiments demonstrated that the reaction underwent an unprecedented dual nucleophilic substitution/radical addition process, in which sodium sulfinates were used not only as nucleophiles but also as a sulfonyl radical source.

Iron-Mediated Reductive Amidation of Triazine Esters with Nitroarenes.

A reductive amidation of triazine esters with nitroarenes by using cheap iron as a reducing metal in the presence of TMSCl in DMF was developed. The reactions proceeded efficiently under transition metal-free conditions to give the corresponding amides in moderate to good yields with good functional group compatibility. Preliminary mechanistic investigations indicated that nitrosobenzene, N-phenyl hydroxylamine, azoxybenzene, azobenzene, aniline, and N-arylformamide possibly served as the intermediates of the reaction.

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity.

The electroreductive coupling of 2-acylbenzoates with acrylonitrile in the presence of TMSCl and successive treatment with 1 M HCl gave 2-cyanonaphthalen-1-ols or 3-(3-cyanoethyl)phthalides. On the other hand, the reaction of 2-acylbenzoates with methyl vinyl ketone under the same conditions produced 3-(3-oxobutyl)phthalides as the sole products. What determines the product selectivity was studied using DFT calculations.

Electroreductive Coupling of Phthalimides with α,β-Unsaturated Carbonyl Compounds and Subsequent Acid-Catalyzed Rearrangement to 4-Aminonaphthalen-1-ols: Density Functional Theory Study of the Acid-Catalyzed Rearrangement of Ketene Silyl Acetals.

The electroreductive coupling of phthalimides with α,β-unsaturated carbonyl compounds in the presence of TMSCl and successive treatment of the electrochemically coupled products with TFA gave two types of rearranged products, 3- and 2-substituted 4-aminonaphthalen-1-ols. The substituent (R) on the nitrogen atom of phthalimides determined which type of 4-aminonaphthalen-1-ol was preferentially formed. Bulky and less bulky N substituents selectively afforded 3- and 2-substituted 4-aminonaphthalen-1-ols, respectively. It was presumed by the density functional theory calculations for the acid-catalyzed rearrangement of silyl ketene acetals produced by the electroreductive coupling that the rearranged product selectivity depends on whether O or N protonation of the amide group of the silyl ketene acetals occurs more rapidly.

Electroreductive Coupling of Phthalic Anhydrides with α,β-Unsaturated Carbonyl Compounds: Synthesis of 1,4-Dihydroxynaphthalenes.

Electroreductive coupling of phthalic anhydrides with α,β-unsaturated carbonyl compounds in the presence of TMSCl and subsequent treatment with 1 M HCl gave 1,4-dihydroxynaphthalenes and 2-methyl-2,3-dihydronaphthalene-1,4-diones.

High yielding protocol for direct conversion of thiols to sulfonyl chlorides and sulfonamides

ABSTRACTIn this paper, a new method for oxidative chlorination of thiols to sulfonyl chlorides and sulfonamides using H2O2 in the presence of TMSCl is reported. The excellent yields, short reaction times, excellent efficiencies, low costs, and easy separation of products are the most important advantages of this method.

Switchable regioselection of C-H thiolation of indoles using different TMS counterions.

A switchable regioselectivity in C-H thiolation reaction by simply swapping the counteranions of TMS is reported here for the first time. An exclusive C3-H thiolation of indoles with sodium arylsulfinates was achieved in the presence of TMSCl as a promoter. In contrast, with the use of TMSOTf instead of TMSCl under otherwise identical conditions, a regiospecific C2-H thiolation of indoles was realized with the same set of substrates.

3 + 2] Cycloaddition of Oxazol-5-(4H)-ones with Nitrones for Diastereoselective Synthesis of Isoxazolidin-5-ones.

In the presence of TMSCl, the [3 + 2] cycloaddition of oxazol-5-(4H)-ones with nitrones proceeded smoothly and furnished the desired isoxazolidin-5-ones with high diastereoselectivities in reasonable chemical yields. The chemical structure of the title compounds was firmly confirmed by X-ray single-crystal structure analysis.

Acceleration of metallacycle-mediated alkyne–alkyne cross-coupling with TMSCl

Investigation of titanium-centered metallacycle-mediated cross-coupling between unsymmetrical internal alkynes has led to the discovery that TMSCl significantly accelerates the CC bond forming event. We report a collection of results that compare the efficiency of this reaction employing Ti(Oi-Pr)4/2n-BuLi in PhMe with and without TMSCl, demonstrating in every case that the presence of TMSCl has a profound impact on efficiency. While relevant in the context of developing this fundamental bond-forming process as an entry to more complex organometallic transformations, these modified reaction conditions allow coupling processes to be run at >10 times the concentrations previously possible [in 2.4M n-BuLi (hexanes)], without the requirement of additional solvent. Finally, we demonstrate the effectiveness of these modified reaction conditions for the annulative cross-coupling between TMS-alkynes and 1,6-enynes leading to the formation of angularly substituted hydrindanes with, now well appreciated, high levels of regio- and stereoselection.

ChemInform Abstract: Electroreductive Coupling of 1,3‐Dimethyluracils with Aromatic Ketones: Synthesis of 6‐Substituted 1,3‐Dimethyluracils.

AbstractElectroreductive coupling of uracils (I) and (VI) with benzophenones or alkylphenylketones in the presence of TmsCl provides 6‐substituted uracils.

Synthesis and fungicidal activity of novel 2-aryl-3-(1,3,4-thiadiazolyl)-6(8)-methyl-1,3-benzoxazines.

A class of novel 2-aryl-3-(1,3,4-thiadiazolyl)-6(8)-methyl-1,3-benzoxazines was prepared by reactions of 2-methyl-6-((1,3,4-thiadiazolylamino)methyl)phenols or 4-methyl-2-((1,3,4-thiadiazolylamino)methyl)phenols and 2- or 4-nitrobenzaldehyde in the presence of TMSCl in refluxing toluene. The electron-donating methyl group on the benzene ring played an essential role on the reactivity of the substituted phenols, which was proved by DFT calculation. The fungicidal activity of the resultant products were also preliminarily evaluated, most of which displayed moderate to good fungicidal activity. Especially, compound 6f showed 98.0% activity against Sclerotonia sclerotiorum and Botrytis cinerea at concentration of 25μg/mL.

ChemInform Abstract: Lewis Acid Mediated Tandem Reaction of Propargylic Alcohols to Tetrazoles Involving C—O‐ and C—C‐Bond Cleavage Reactions and a C—N‐Bond Formation.

A novel and direct synthesis of 1-aryl-5-arylvinyltetrazoles from easily prepared propargylic alcohols and TMSN3 is developed in the presence of TMSCl under mild conditions (TMS=trimethylsilyl). The process involves an allenylazide intermediate, followed by a C-C-bond cleavage and C-N-bond formation to afford the desired products. Moreover, this method offers a good functional-group applicability and can be scaled-up to grams (yield up to 85 %).

Lewis Acid Mediated Tandem Reaction of Propargylic Alcohols to Tetrazoles Involving CO‐ and CC‐Bond Cleavage Reactions and a CN‐Bond Formation

A novel and direct synthesis of 1-aryl-5-arylvinyl-tetrazoles from easily prepared propargylic alcohols and TMSN3 is developed in the presence of TMSCl under mild conditions (TMS = trimethylsilyl). The process involves an allenylazide intermediate, followed by a C-C-bond cleavage and C-N-bond formation to afford the desired products. Moreover, this method offers a good functional-group applicability and can be scaled-up to grams (yield up to 85 %).

ChemInform Abstract: Synthesis of Pyrazolo[3,4‐d]‐4,5‐dihydropyrimidines Through [5 + 1] Cyclocondensation.

AbstractMore than twenty pyrazolodihydropyrimidine derivatives are prepared through condensation of secondary amidines with aromatic aldehydes in the presence of TmsCl as activator for the CO‐group and water scavenger.

ChemInform Abstract: Amide Activation by TMSCl: Reduction of Amides to Amines by LiAlH4 under Mild Conditions.

AbstractLiAlH4 in the presence of TmsCl as activating agent is found to be efficient to reduce even tertiary and secondary amides to the corresponding amines.

A three-component reaction of C,N-cyclic N′-acyl azomethine imines, isocyanides, and azide compounds: effective synthesis of 1,5-disubstituted tetrazoles with tetrahydroisoquinoline skeletons

A multicomponent reaction of isocyanides and C,N-cyclic N'-acyl azomethine imines in the presence of TMSCl and NaN3 leads to tetrazole derivatives. These reactions proceeded cleanly to afford the corresponding 1,5-disubstituted tetrazoles containing a tetrahydroisoquinoline skeleton in high to excellent yields.

Chlorosilane-Promoted Addition Reaction of Isocyanides to 3,4-Dihydroisoquinoline N-Oxides

The addition reaction of isocyanides to 3,4-dihydroisoquinoline N-oxides in the presence of TMSCl has been demonstrated, with the corresponding 1,2,3,4-tetrahydroisoquinoline-1-carboxylamides being obtained in moderate to high yields. A wide range of 3,4-dihydroisoquinoline N-oxides and isocyanides were applicable to this reaction.

ChemInform Abstract: Pd‐Catalyzed Reductive Cleavage of Alkyl Aryl Sulfides with Triethylsilane that Is Accelerated by Trialkylsilyl Chloride.

AbstractThe process is accelerated and exhibits increased functional group selectivity in the presence of TmsCl as the additive.

Synthesis and Fungicidal Activity of Novel 2,3-Disubstituted-1,3-benzoxazines

A series of new 2,3-disubstituted-3,4-dihydro-2H-1,3-benzoxazines were prepared in moderate to excellent yields by aza-acetalizations of aromatic aldehydes with 2-(N-substituted aminomethyl)phenols in the presence of TMSCl. Their structures were confirmed by IR, 1H-NMR, 13C-NMR, MS and elemental analysis. The fungicidal activities of the target compounds were preliminarily evaluated, and some compounds exhibited good activity against Rhizoctonia solani.

Pd-catalyzed reductive cleavage of alkyl aryl sulfides with triethylsilane that is accelerated by trialkylsilyl chloride

The palladium-catalyzed reductive cleavage of alkyl aryl sulfides to afford the corresponding arenes in high yield, which is both accelerated and exhibits increased functional group selectivity in the presence of TMSCl, is described. This ligand-free reaction features mild conditions, easy operation, use of readily available reagents, and high functional group selectivity.