Indium-mediated mild and efficient one-pot synthesis of alkyl phenyl selenides

A mild and convenient one-pot process for synthesizing alkyl phenyl selenides is developed using indium metal. The reaction shows the selectivity for tert-alkyl, benzylic, and allylic halides over primary and secondary alkyl halides.     

One-pot synthetic method of unsymmetrical diorganyl selenides: reaction of diphenyl diselenide with alkyl halides in the presence of lanthanum metal

A convenient synthetic method of unsymmetrical selenides has been developed. When diphenyl diselenide was allowed to react with two equimolar amounts of primary alkyl iodides and bromides in the presence of an equimolar amount of lanthanum metal, alkyl phenyl selenides were formed in moderate to good yields. For the reaction of primary alkyl chlorides and secondary alkyl iodides, the yields of the selenides were low; however, the yields were dramatically improved by the addition of TMEDA or HMPA. A reaction pathway involving the generation of a lanthanum phenylselenolate intermediate was suggested.     

Convenient One‐Pot Synthesis of Vinyl Ethers from Phenyl 2‐Hydroxyalkyl Selenides

Vinyl ethers were prepared with good yields in a one‐pot, two‐step transformation by O‐alkylation reaction of phenyl 2‐hydroxyalkyl selenides with primary or secondary organic halides followed by oxidation elimination with 30% hydrogen peroxide.     

Rate Study of Samarium Diiodide Reduction of Alkyl Halides and 2-Heptanone

Rate constants directly measured from GC-analyzed method for SmI₂ reduction of alkyl halides were obtained. The rates increase in the orders of primary, secondary, tertiary RX and RCl < RBr < RI as expected. 2-Heptanone was chosen as the partner of alkyl halide in the samarium Barbier reaction. In the absence of HMPA, the reaction orders of alkyl halide and ketone were determined as first and zero order, respectively.     

Cobalt-Catalyzed Asymmetric Remote Borylation of Alkyl Halides

Enantioselective functionalization of racemic alkyl halides is an efficient strategy to assemble complex chiral molecules, but remains one of the biggest challenges in organic chemistry. The distant and selective activation of unreactive C−H bonds in alkyl halides has received growing interest as it enables rapid generation of molecular complexity from simple building blocks. Here, we reported a cobalt-catalyzed remote borylation of alkyl (pseudo)halides (alkyl−X, X=I, Br, Cl, OTs) with pinacolborane (HBpin) and presented a robust approach for the generation of valuable chiral secondary organoboronates from racemic alkyl halides. This migration borylation reaction is compatible with primary, secondary, and tertiary bromides, offering direct access to a broad range of alkylboronates. The extension of this catalytic system to the borylation of aryl halides was also demonstrated. Preliminary mechanistic studies revealed that this remote borylation involved a radical reaction pathway.     

2-Hydroxy-N,N,N-tributylethanaminium thiocyanate as solvent and reagent for the preparation of alkyl thiocyanates

2-Hydroxy-N,N,N-tributylethanaminium thiocyanate was utilized as both solvent and reagent for the conversion of alkyl halides to the corresponding alkyl thiocyanates in good yields under mild conditions.     

A Facile One-pot Method for the Synthesis of Vinyl Ethers from 2-Hydroxyalkyl Phenyl Selenides

chloride instead of primary or secondary organic halide, only 21% isolated yield of 1-tert-butoxy-1-phenylethene was obtained. Obviously, t-butyl chloride would tend to mainly take place the elimination reaction rather than the substitution reaction under sodium alkylate. Scheme 1 R1OHPhSe R2R3CHX 2NaH/THFR1OPhSeCHR2R3R1 OCHR2R3H2O21 3 4 Table 1 Preparation of vinyl ethers from 2-hydroxyalkyl phenyl selenides Entry R1 R2R3X Product a Yield (%) b 1 C6H5 CH2=CHCH2Br 4a 83 …     

Aminomethylation of organic halides promoted by zinc in protic medium

Organic halides undergo smooth aminomethylation by secondary amines and aqueous formaldehyde promoted by metallic zinc under copper(I) catalysis. Good to excellent yields are obtained with primary, secondary, and tertiary iodides, allylic, propargylic, and benzylic bromides and with α-bromoesters. In most cases, DMSO is the best solvent, but dioxane is preferable for some more reactive halides. Additional experiments with radical quenchers and promoters and the use of ‘radical clocks’ indicate a stepwise reaction mechanism initiated by the attack of an alkyl radical to iminium ion.     

Triton-B catalyzed, efficient one-pot synthesis of carbazates

A quick and efficient, one-pot synthesis of carbazates was accomplished in high yields by the reaction of various primary, secondary, and tertiary alkyl halides with a variety of substituted hydrazines using the benzyltrimethylammonium hydroxide (Triton-B)/CO₂ system. The reaction conditions are mild with simpler work-up procedures than the reported methods. Correspondence: Devdutt Chaturvedi, Bio-Organic Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu-Tawi 18000, J&K, India.     

A Novel One‐Step Synthesis of Symmetrical Dialkyl Trithiocarbonates in the Presence of Phase‐Transfer Catalysis

Symmetrical trithiocarbonates were directly obtained, in moderate to excellent isolated yields, by the reaction of various primary, secondary, allylic and benzylic halides or alkyl tosylates with a suspension of granulated KOH and alumina in CS₂ under phase‐transfer catalysis. In this manner, cyclic trithiocarbonates such as 1,3‐dithiolane‐2‐thione can also be prepared without formation of any polymeric by‐products.     

Triton-B catalyzed,efficient one-pot synthesis of dithiocarbazates

A quick and efficient, one-pot synthesis of dithiocarbazates was accomplished in high yields by the reaction of various primary, secondary, and tert. alkyl halides with a variety of substituted hydrazines using the benzyl-trimethylammonium hydroxide (Triton-B)/CS₂ system. The reaction conditions are mild with simpler work-up procedures than the reported methods. Correspondence: Devdutt Chaturvedi, Medicinal and Process Chemistry Division, Central Drug Research Institute, Lucknow-226001, U.P., India.     

Synthesis and reaction of selenocarbamic acid sodium and potassium salts and organo-germanium, -tin,and -lead esters

Sodium 2 and potassium selenocarbamates 3 were found to be synthesized in moderate to good yields by the reaction of carbamoyl chlorides with sodium and potassium selenides. The salts 2 and 3 reacted with alkyl halides and organo-germanium, -tin, and -lead chlorides to give the corresponding esters 7–9 in good yields.     

Rapid Synthesis of Alkyloxy Porphyrins Under Microwave Irradiation

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.     

A Structure–Activity Study of Nickel NNN Pincer Complexes for Alkyl‐Alkyl Kumada and Suzuki–Miyaura Coupling Reactions

A new series of Ni NNN pincer complexes were synthesized and characterized. The main difference among these complexes is the substituents on the side arm amino group(s). No major structural difference was found except for the C–N–C angle of the various substituents and the ‘pseudo bite angle’ of the complexes. Four new complexes were efficient for the alkyl‐alkyl Kumada reaction of primary alkyl halides, and among them, one complex was also efficient with secondary alkyl halides. The influence of the substituents on the catalytic performance of the Ni complexes in alkyl‐alkyl Kumada and Suzuki–Miyaura cross‐coupling reactions was systematically investigated. No correlation was found between the catalytic activity and the key structural parameters (C–N–C angle and ‘pseudo bite angle’), redox properties or Lewis acidity of the complexes.     

Indium(I) iodide-promoted cleavage of diaryl diselenides and disulfides and subsequent condensation with alkyl or acyl halides. One-pot efficient synthesis of diorganyl selenides, sulfides, selenoesters, and thioesters

Diphenyl diselenides and disulfides undergo facile cleavages by indium(I) iodide and the corresponding generated selenate and thiolate anions condense in situ with alkyl or acyl halides present in the reaction mixture. Thus, a simple, efficient, and general procedure has been developed for the synthesis of unsymmetrical diorganyl selenides, sulfides (thioethers), selenoesters, and thioesters by this one-pot reaction at room temperature.     

Triton B–Mediated Mild,Convenient, and Efficient Method for the Selective Alkylation of Cyclic Secondary Amines and Thiols

Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium.     

Reactions of Selenobenzamide and Alkyl Halides. Synthesis of Dialkyl Selenides and Diselenides

In the absence of base, the reaction of selenooenzamide with alkyl halides gives the dialkyl diselenides as the major product. While the reaction of selenobenzamide and an alkyl halide is carried out in a 1:2 molar ratio and in the presence of strong base, the dialkyl selenides predominate.     

Zn/CuI-mediated coupling of alkyl halides with vinyl sulfones, vinyl sulfonates, and vinyl sulfonamides

A novel high-yielding Zn/CuI-mediated coupling method of alkyl halides with vinyl sulfones, vinyl sulfonates, and vinyl sulfonamides is described. This protocol is applicable for primary, secondary, and tertiary alkyl iodides and bromides. Alkyl chlorides and aryl and vinyl halides were unreactive under the reaction conditions. Formamide was found to be a superior solvent for obtaining high yields.     

Zinc‐Catalyzed Borylation of Primary,Secondary and Tertiary Alkyl Halides with Alkoxy Diboron Reagents at Room Temperature

A new catalytic system based on a Zn^II 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.     

Reduced Species （HSO2^-, SO2^·-） Promoted One-Pot Efficient Synthesis of Phenyl Alkyl Selenides

Reduced species （HSO2^-, SO2^·-） promoted one-pot synthesis of phenyl alkyl selenides has been developed. This synthetic method was achieved by reactions of diphenyl diselenide with alkyl halides at room temperature. It is noteworthy that the reactions were operated under mild reaction conditions, required short time, and got good resuits. A single electron transfer reaction mechanism was proposed for the reaction.