A High Yielding, One-Pot, Triton-B Catalyzed Synthesis of Dithiocarbamates Using Alcoholic Tosylates

Summary. A novel process for the one-step chemoselective conversion of alcoholic tosylates into dithiocarbamates as protected amines was developed using benzyltrimethylammoniumhydroxide (Triton-B) in presence of carbon disulfide. Thus, dithiocarbamates of different amines were prepared in very good to excellent yields. This protocol is mild, chemoselective, and efficient compared to other reported methods. Present address: Institute of Organic and Biomolecular Chemistry, Georg-August University, D-37077, G?ttingen, Germany     

Triton-B Catalyzed Efficient One-Pot Synthesis of Dithiocarbamate Esters

Summary. A novel process for the one-step chemoselective conversion of alkyl halides into dithiocarbamates as protected amines was developed using benzyltrimethylammonium hydroxide (Triton-B) in presence of carbon disulfide. Thus, dithiocarbamates of different amines were prepared in very good to excellent yields. This protocol is mild, chemoselective, and efficient compared to other methods. Present address: Institute of Organic and Biomolecular Chemistry, Georg–August University, D-37077 G?ttingen, Germany     

An efficient, one-pot, synthesis of dithiocarbamates from the corresponding alcohols using Mitsunobu’s reagent

A Mitsunobu-based protocol has been developed for the synthesis of dithiocarbamates from the corresponding alcohols using carbon disulfide and amines in good to excellent yields. This protocol is mild, chemoselective and efficient compared to other reported methods.     

Chemoselective Catalytic Conjugate Addition of Alcohols over Amines

A highly chemoselective conjugate addition of alcohols in the presence of amines is described. The cooperative nature of the catalyst enabled chemoselective activation of alcohols over amines, allowing the conjugate addition to soft Lewis basic α,β‐unsaturated nitriles. Divergent transformation of the nitrile functionality highlights the utility of the present catalysis.     

Electrogenerated Base-Promoted Synthesis of Dithiocarbamate Acid Esters and 3-(N-Substituted-amino)-2-cyanodithiocrotonates from Primary or Secondary Amines and Carbon Disulfide

Electrogenerated cyanomethyl anion promotes the reaction between primary or secondary amines, carbon disulfide, and alkyl or benzyl halide. Secondary amines are converted to alkyl or benzyl dithiocarbamates, whereas primary amines give N-substituted alkyl or benzyl 3-amino-2-cyanodithiocrotonates. The mechanisms are discussed.     

OH−/Silica-Mediated One-Pot Synthesis of Dithiocarbamates Under Solvent-Free Conditions

Abstract

An efficient, versatile, and environmentally benign method for the synthesis of dithiocarbamates under solvent-free conditions is reported. The Michael addition of electron-deficient alkenes with alkyl or aryl amines and CS₂ in the presence of OH^?/silica in a one-pot three-component reaction protocol gave the corresponding dithiocarbamates in good to excellent yields. This method is suitable for a wide range of amines and a variety of Michael acceptors in solvent-free conditions. The results of the present work show the desired products in excellent yields.     

Ultraviolet spectrophotometric determination of primary and secondary aliphatic amines by formation of dithiocarbamates

Primary and secondary aliphatic amines (ca. 0.2–6 μg ml^?1) determined at 250 and 280 nm, respectively, after in situ derivatization to dithiocarbamates in a carbon disulphide/ aqueous sodium hydroxide two-phase system. Alcohols, aromatic and tertiary amines do not interfere.     

无溶剂无催化剂条件下二硫代氨基甲酸酯衍生物的合成研究

主要研究了二硫代氨基甲酸酯衍生物的合成,将脂肪胺、CS2与α,β-不饱和羰基化合物或卤代烃在无溶剂无催化剂室温条件下,"一锅法"进行了Michael-type的加成反应,合成了二硫代氨基甲酸酯衍生物.该方法产率高,操作简单,是一种原子经济的合成方法,并可大规模地用于制药及农药方面.     

A convenient method for the synthesis of substituted thioureas

A convenient method for the synthesis of substituted thioureas by the reaction of primary amines with molybdenum dialkyl dithiocarbamates has been developed. Primary amines on reaction with 0.5 equiv of molybdenum xanthate produce the corresponding thioureas in moderate to good yields in short times. Similar reactions with propargylamine or 2-aminoethanol produce cyclic thiaoxazolidine and oxazolidine derivatives, respectively.     

A novel isocyanide-based three-component reaction: a facile synthesis of substituted 2H-pyran-3,4-dicarboxylates

An efficient method for synthesis of 2H-pyran-3,4-dicarboxylates using the three-component reaction of dithiocarbamates, dialkyl acetylenedicarboxylates, and isocyanides in solvent-free conditions is described. In these reactions, synthesis of dithiocarbamates is possibly based on the one-pot reaction of secondary amines, CS₂, and alkyl halides in solvent-free conditions without using a catalyst. The mild reaction conditions and high yields of the reaction exhibit the good synthetic advantage of these methods.     

Thiocarbamoylation of amine-containing compounds

Thiocarbamoylation of aliphatic amines with tetramethylthiuram disulfide (TMTD) was studied. The reactions were established to proceed according to a two-stage mechanism. In the first stage,S-(thiocarbamoyl)thiohydroxylamines and dimethyl dithiocarbamates are formed. The latter exist in equilibrium with dimethyldithiocarbamic acid, which can undergo decomposition to give dimethylamine and carbon disulfide. In the second stage, several competitive transformations of these intermediates into the final products occur,viz., (1) the reactions of CS₂ with primary amines on heating (70–110 °C) yield mixed and symmetrical thioureas and the reactions of CS₂ with secondary amines give symmetrical dithiocarbamates, and (2) insertion of CS₂ intoS-(thiocarbamoyl)thiohydroxylamines affords thiuram disulfides. Thiuram disulfides formed from primary amines decompose to give isothiocyanates, which are converted into thioureas by condensation with amines, whereas thiuram disulfides which are obtained in the reactions with secondary amines and which cannot form thioureas react with amines analogously to TMTD. For Part 4, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 334–342, February, 2000.     

Versatile and Large-Scale Synthesis of Functional Dithiocarbamates in Water

Structural diversity is possible in direct access to functional dithiocarbamates based on a highly efficient and simple one-pot reaction of CS₂, amines, and alkyl halides in nearly quantitative yields in water.     

Analytical applications of the amine-carbon disulphide reaction in acetonitrile

The ease with which carbon disulphide transforms primary and secondary amines in acetonitrile medium into the corresponding monoalkylammonium monoalkyldithiocarbamates and dialkylammonium dialkyldithiocarbamates respectively and the simplicity and reliability of potentiometric and spectrophotometric determination of dithiocarbamates with copper(I) perchlorate in the same medium, provide simple, accurate and reliable methods for the determination of primary and secondary amines and of organic isothiocyanates.     

A facile protocol for N-Cbz protection of amines in PEG-600

正An efficient and eco-friendly protocol for the chemoselective N-benzyloxycarbonylation of amines was described.The reaction of amines with benzyl chloroformate(Cbz-Cl) in the presence of PEG-600 at room temperature afforded the corresponding N-Cbz derivatives in excellent yields.The method is applicable to the N-Cbz protection of aliphatic(acyclic and cyclic) and aromatic amines.     

An efficient and chemoselective Cbz-protection of amines using silica-sulfuric acid at room temperature

A simple, facile, and chemoselective N-benzyloxycarbonylation of amines using silica-sulfuric acid that proceeds under solvent-free conditions at room temperature has been achieved. These reactions are applicable to a wide variety of primary (aliphatic and cyclic) secondary amines, amino alcohols, and heterocyclic amines.     

Copper-catalyzed reductive coupling of tosylhydrazones with amines: a convenient route to α-branched amines

A general procedure for the reductive coupling of N-tosylhydrazones with amines in the presence of Cu(acac)(2) and Cs(2)CO(3) has been developed. The protocol is very effective and chemoselective with various primary and secondary aliphatic amines, aminoalcohols as well as azole derivatives to give α-branched amines in good yields.     

An Efficient One-Pot Synthesis of 2-Hydroxyalkyl Dithiocarbamates

Abstract

In the presence of anhydrous potassium phosphate, epoxides reacted with carbon disulfide and primary or secondary amines in acetone to give the corresponding 2-hydroxyalkyl dithiocarbamates regioselectively in moderate to good yield.     

Highly chemoselective metal-free reduction of tertiary amides

This communication describes the chemoselective metal-free reduction of tertiary amides to the corresponding amines. Hantzsch ester is used as a mild reducing agent for the reduction of trifluoromethanesulfonic anhydride activated amides providing the tertiary amines with high functional group tolerance.     

Cesium effect: high chemoselectivity in direct N-alkylation of amines

A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondary amines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondary amines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated this methodology was highly chemoselective to favor mono-N-alkylation over dialkylation. In particular, use of either sterically demanding substrates or amino acid derivatives afforded the secondary amines exclusively, offering wide applications in peptidomimetic syntheses.     

Triton-B Catalyzed, Efficient, One-Pot Synthesis of Carbamate Esters from Alcoholic Tosylates

A novel process for the one-step chemoselective conversion of a variety of alcoholic tosylates into carbamates serving as protected amines was developed using benzyltrimethylammonium hydroxide (Triton-B) in the presence of gaseous carbon dioxide. Thus carbamate esters of different amines were prepared in very good to excellent yields.