New method for the synthesis of trialkyl(triorganylsilylalkylthio)silanes and trialkyl(triorganylsilylalkylthio)germanes

Conclusions A new method was developed for the synthesis of trialkyl(triorganylsilylalkylthio)silanes and trialkyl(triorganylsilylalkylthio)germanes with the general formula R₃MS(CH₂)_nSiR₃ ' (M=Si or Ge) by the reaction of the corresponding triorganylsilylalkenethiols with bis(trialkylsilyl)mercury or bis(trialkylgermyl)mercury.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2401–2402, October, 1984.     

Acyl iodides in organic synthesis: VII. Reactions with trialkyl(alkynyl)silanes,-germanes, and-stannanes

Reactions of acyl iodides R¹COI (R¹=Me, Ph) with trialkyl(alkynyl)silanes,-germanes, and stannanes (R²C≡CMR ₃ ³ ; M=Si, Ge, Sn) were studied. Acyl iodides reacted with the germanium and tin derivatives with cleavage of the M-C_sp bond and formation of the corresponding trialkyl(iodo)germanes and-stannanes R ₃ ³ MI (M=Ge, Sn) and alkynyl ketones R¹C(O)C≡CR² and R¹C(O)C≡CC(O)R¹. By contrast, the reaction of acetyl iodide with ethynyl(trimethyl)silane gave only a small amount of 1,2-diiodovinyl(trimethyl) silance as a result of iodine addition at the triple bond. Bis(trimethylsilyl)ethyne failed to react with acetyl iodide.     

Re(VII) extraction and separation from Mo(VI) by levextrel resins containing trialkyl amine

A synthetic method of novel trialkyl amine (N235, R₃N, R = C₈–C₁₀) Levextrel resin was described in this paper. The extraction behavior of rhenium(VII) and molybdenum(VI) with this N235 Levextrel resin has been studied. The mechanism of extraction of Re(VII) with the N235 Levextrel resin has been discussed briefly through equi-molar series method and the conventional slope analysis method. The optimal conditions of extraction and separation Mo(VI) and Re(VII) with the N235 Levextrel resin were determined. Also, its excellent extraction characteristics for Re(VII) were confirmed by extraction and stripping tests in a analog liquid solution containing Mo(VI) and Re(VII).     

Designing Cross-Coupling Reactions using Aryl(trialkyl)silanes

Organo(trialkyl)silanes have several advantages, including high stability, low toxicity, good solubility, easy handling, and ready availability compared with heteroatom-substituted silanes. However, methods for the cross-coupling of organo(trialkyl)silanes are limited, most probably because of their exceeding robustness. Thus, a practical method for the cross-coupling of organo(trialkyl)silanes has been a long-standing challenging research target. This article discusses how aryl(trialkyl)silanes can be used in cross-coupling reactions. A pioneering example is Cu^II catalytic conditions with the use of electron-accepting aryl- or heteroaryl(triethyl)silanes and aryl iodides. The reaction forms biaryls or teraryls. This design concept can be extended to Pd/Cu^II-catalyzed cross-coupling polymerization reactions between such silanes and aryl bromides or chlorides and to Cu^I-catalyzed alkylation using alkyl halides.     

Three-component reaction between 5,5-diarylthiohydantoins and acetylenic esters in the presence of trialkyl phosphite

Abstract  

The adducts produced in the reaction between trialkyl phosphites and acetylenic esters were trapped by thiohydantoins to produce highly functionalized 5-oxo-2-thioxoimidazolidines and 4,5-dihydro-2-(methylthio)-5-oxoimidazoles in good yields.     

One-pot solvent-free synthesis of triaryl- and triheteroarylmethanes by Bi(OTf)3-catalyzed Friedel-Crafts reaction of arenes/heteroarenes with trialkyl orthoformates

A convenient, practical and highly efficient one-pot method has been developed for the synthesis of triaryl- and triheteroarylmethane derivatives by Bi(OTf)₃-catalyzed Friedel-Crafts alkylation of trialkyl orthoformates in combination with a wide variety of arenes/heteroarenes at room temperature under solvent-free conditions and in an air atmosphere. The methodology offers an operational simplicity, high atom economy and environmentally benign procedure. Furthermore, selected compound 3k showed promising anti-inflammatory activity with inhibition nitric oxide and did not exhibit significant cytotoxic effects on macrophage cells.     

Molecular structure and theoretical studies of new stable phosphorus ylides derived from trialkyl phosphites

The reaction between dialkyl acetylenedicarboxylates and NH heterocyclic compounds in the presence of trialkyl phosphite leads to stable phosphorus ylide derivatives in good yields. The x‐ray crystallographic data and theoretical study show that there is a resonance between two bonds of C₉P₁ and C₉₁O₉₁ in phosphorous ylide 4c . This compound crystallizes in the triclinic system, space group ( ), with the following unit cell parameters: a = 8.7522(3)Å, b = 8.8513(5)Å, c = 18.3469(5)Å, α = 99.1220(10)°, β = 90.954(2)°, γ = 118.792(2)°, Z = 2, and V = 1222.72(9)ų. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:36–43, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20653     

The preparation of sol-gel materials doped with ionic liquids and trialkyl phosphine oxides for yttrium(III) uptake

A new material (IL923SGs) composed of ionic liquids and trialkyl phosphine oxides (Cyanex 923) for Y(III) uptake was prepared via a sol-gel method. The hydrophobic ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate (C₈mim⁺PF₆⁻) was used as solvent medium and pore templating material. The extraction of Y(III) by IL923SGs was mainly due to the complexation of metal ions with Cyanex 923 doped in the solid silica. Ionic liquid was stably doped into the silica gel matrix providing a diffusion medium for Cyanex 923, and this will result in higher removal efficiencies and excellent stability for metal ions separation. IL923SGs were also easily regenerated and reused in the subsequent removal of Y(III) in four cycles.     

Infrared absorption spectra of trialkyl orthovanadates

Conclusions The IR spectra of seven trialkyl orthovanadates were studied. The absorption bands of the V=O and V-O bonds in the spectra of these compounds are found respectively in the 960–1012 and 600–662 cm^–1 regions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2812–2814, December, 1972.     

C3‐symmetric trialkyl phosphites as starting compounds of asymmetric synthesis

Chiral C₃‐symmetric trialkyl phosphites, derivatives, of (−)‐(1R,2S,5R)‐menthol, and (−)‐di‐O‐isopropylidene‐1,2:5,6‐α‐D ‐glucofuranose, have been studied as starting reagents for the preparation of chiral organophosphorus compounds. The reactions involve induction at the α‐carbon atom of substituted α‐alkylphosphonates. The stereoselectivity of the reaction depends on the structure of the starting compounds and the reaction conditions. The configurations of the alkylphosphonates were defined by means of NMR spectroscopy and by transformation into corresponding alkylphosphonic acids. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:138–143, 2000     

First asymmetric Abramov-type phosphonylation of aldehydes with trialkyl phosphites catalyzed by chiral Lewis bases

Chiral phosphine oxides (Lewis bases) catalyze silicon tetrachloride-mediated, enantioselective phosphonylation of aldehydes with trialkyl phosphites (Abramov-type reaction), which leads to optically active α-hydroxyphosphonates with moderate enantioselectivities. ³¹P NMR analysis of the phosphonylation of benzaldehyde with triethyl phosphite supports the assumed reaction mechanism.     

Enantioselective reduction of ketones with NaBH4/diglyme possibly catalysed by trialkyl borate: optically active sec-alcohols from prochiral ketones with catalytic (−)-menthol: autocatalysis option

Ketones can be reduced with NaBH₄ in diglyme without an apparent proton source, but putatively catalysed by a trialkyl borate. This can be initially derived in situ from NaBH₄ and an alcohol, although the reaction becomes increasingly autocatalytic with time. With (−)-menthol as the initiating alcohol, the enantioselective reductions of a range of prochiral ketones in quantitative yields and moderate ees (generally 58–87%) were realised (the autocatalysis was demonstrated in two cases; catalysis by tris-(−)-menthyl borate was demonstrated in one case). The mechanism may involve either the activation of the substrate (electrophilically) or of the hydride reagent (nucleophilically). This method offers a relatively simple and inexpensive approach to a key transformation in asymmetric synthesis.     

Electrochemically induced processes in the formation of phosphorus acid derivatives. 1. Synthesis of trialkyl phosphates from white phosphorus

An electrochemical method, based on the joint action of nucleophilic and electrophilic reagents on P₄, is proposed in order to utilize white phosphorus in the formation of the esters of phosphorus acids. The action of alkoxide ions on white phosphorus in an alcohol medium in the presence of iodine generated at the anode leads to the formation of phosphate esters. A scheme in which the intermediate products are dialkyl and trialkyl phosphites and the side product is dialkyl alkylphosphonate is proposed for the process.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420028 Kazan'. V. I. Ul'yanov-Lenin Kazan State University, 420028 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1322–1328, June, 1992.     

Regiodirected Synthesis and Stereochemistry of 2,4,8‐Trialkyl‐3‐thia‐1,5‐diazabicyclo[3.2.1]octanes and α,ω‐Bis(2,4,6‐trialkyl‐1,3,5‐dithiazinane‐5‐yl)alkanes

2,4,8‐Trialkyl‐3‐thia‐1,5‐diazabicyclo[3.2.1]octanes have been obtained by the regioselective and stereoselective cyclocondensation of 1,2‐ethanediamine with aldehydes RCHO (R═Me, Et, Prⁿ, Buⁿ, Pentⁿ) and H₂S at molar ratio 1:3:2 at 0°C. The increase in molar ratio of thiomethylation mixture RCHO–H₂S (6:4) at 40°C resulted in selective formation of bis‐(2,4,6‐trialkyl‐1,3,5‐dithiazinane‐5‐yl)ethanes. Cyclothiomethylation of aliphatic α,ω‐diamines with aldehydes RCHO (R═Me, Et) and H₂S at molar ratio 1:6:4 and at 40°С led to α,ω‐bis(2,4,6‐trialkyl‐1,3,5‐dithiazinane‐5‐yl)alkanes. Stereochemistry of 2,4,8‐trialkyl‐3‐thia‐1,5‐diazabicyclo[3.2.1]octanes have been determined by means of ¹H and ¹³С NMR spectroscopy and further supported by DFT calculations at the B3LYP/6‐31G(d,p) level. The structure of α,ω‐bis(2,4,6‐trialkyl‐1,3,5‐dithiazinane‐5‐yl)alkanes was confirmed by single‐crystal X‐ray diffraction study.     

Azirine/Oxindole Ring Enlargement via Amidinium Intermediates

A novel general method for the synthesis of oxindoles, namely the ‘azirine/oxindole ring enlargement via amidinium‐intermediates’ has been established: the reaction of 2H‐azirin‐3‐amines 1 with BF₃?OEt₂ in THF solution at ?78° leads to 1,3,3‐trialkyl‐2‐amino‐3H‐indolium tetrafluoroborates 14 in good yields (Scheme 5). Treatment of aqueous solutions of 14 at 0° with aqueous NaOH (30%) and extraction with CH₂Cl₂ gives oily substances that are either hydrates of 1,3,3‐trialkyl‐2‐dihydroindol‐2‐imines 15 or the corresponding indolium hydroxides. These products are transformed to the corresponding 1,3,3‐trialkyl‐2,3‐dihydroindol‐2‐ones 17 in modest yields upon refluxing in H₂O/THF. Reaction of 14 with Ac₂O in pyridine at ca. 23° for 16 h followed by aqueous workup and chromatographic separation leads to mixtures of N‐(1,3,3‐trialkyl‐2,3‐dihydro‐indol‐2‐yliden)acetamides 16 and oxindoles 17 (Scheme 6). Hydrolysis of 16 with aqueous HCl under reflux for 1–2 h gives oxindoles 17 in a good yield. Several oxindoles, spiro‐oxindoles, and 5‐substituted oxindoles were synthesized by means of the reactions mentioned above.     

Nitrogen-containing organosilicon compounds

Fifteen previously unknown piperidinosilanes of the type R_4–m Si[(CH₂) _n NC₅H₁₀] _m (m=1–3; n=0–3). have been synthesized by the reaction of piperidine with diethylaminotrimethylsilane, bis(diethylamino)dimethylsilane, chlorobis(dimethylamino)methylsilane, trichloro(methyl)silane, trialkyl(chloromethyl)silanes, dialkoxy(alkyl)(chloromethyl)silanes, trialkylvinylsilanes, trialkyl(3-chloropropyl)silanes, and 3-chloropropyl(diethoxy)methylsilane. The piperidinosilanes (n>0) have been converted into the corresponding hydrochlorides and methiodides.For part VIII, see [1].     

Synthesis of trialkyl (dialkoxyphosphorylimido)phosphates

Conclusions (Dichlorophosphorylimido)phosphorus trichloride reacts with sodium alcoholates in the corresponding alcohol as the medium to give trialkyl (dialkoxyphosphorylimido)phosphates in 40–90% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1884–1886, August, 1979.     

The preparation of N-substituted aminomethylidenebisphosphonates and their tetraalkyl esters via reaction of isonitriles with trialkyl phosphites and hydrogen chloride. Part 1

The reaction of isonitriles with trialkyl phosphites in the presence of hydrogen chloride gives tetraalkyl N-substituted aminomethylidenebisphosphonates via N-methylideneaminium (isonitrilium) salts. Hydrolysis or dealkylation of these tetraalkyl esters gives N-substituted aminomethylidenebisphosphonic acids in high yields.     

Effect of iodine on the reaction of tetraphosphorus decasulfide with dialkyl disulfides

Elemental iodine decreases the temperature of the reaction of P₄S₁₀ with disulfides which results in the formation of trialkyl tetrathiolothionophosphates, from 100–110 °C to 20–60 °C. The latter decompose to trialkyl tetrathiophosphates.