Metal-Free,One-Pot Oxidative Conversion of Aldehydes to Primary Thioamides in Aqueous Media

One-pot tandem reactions of a variety of aldehydes with aqueous ammonia, molecular iodine, and O,O-diethyl dithiophosphoric acid readily afford the corresponding primary thioamides. This is an inexpensive, practical, and metal-free way of accessing various thioamides from aldehydes in aqueous media. The pure products are obtained simply by filtration followed by successive washing with aqueous sodium thiosulfate and water.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Efficient assembly of α-aryl and α-vinyl nitriles via iron-catalyzed ether bond activation

A novel and practical method for the synthesis of diverse α-aryl and α-vinyl nitriles was developed via an iron-catalyzed sp³ C–O ether bond cleavage with C–C bond formation in the reaction of π-activated ethers with TMSCN.     

Synthesis of 3,4-Dihydrobenzo[h]isoquinoline Derivatives

1-Substituted 3,3,4-trimethyl-3,4-dihydrobenzo[h]isoquinolines have been obtained by the reaction of 1,2-dimethyl-1-(2-naphthyl)-1-propanol with nitriles in conc. H₂SO₄. It was shown that the presence of a benzene ring annelated at positions 7 and 8 of the isoquinoline does not influence reaction of the 1-methyl derivative with isocyanate, however reactions of the 1-methylthio derivative with C and N nucleophiles are affected significantly.     

Synthesis and crystal structure of 7-allylseleno-5-amino-8-cyano-3-ethoxycarbonyl-4-(2-furyl)-1,4-dihydro-2-methyi-1,6-naphthyridine

The reaction of 2-furylmethylideneacetoacetic ester with cyanoselenoacetamide afforded 7-allylseleno-5-amino-S-cyano-3-ethoxycarbonyl-4-(2-furyl)-1,4-dihydro-2-methyl-1,6naphthyridine, the structure of which has been established by X-ray structural study.Translated fromlzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 437–440, February, 1996.     

A theoretical investigation on the cycloaddition reaction between azocarbenium ions and nitriles

The 1,3‐dipolar cycloaddition reactions of the cationic 1,3‐dipolarophiles of azocarbenium ion 1 with HCN in the gas phase were examined using the density functional theory, QCISD method (Quadratic configuration interaction using single and double substitutions) and CCSD(T) (Coupled cluster calculations with single and double excitations and a perturbative estimate of triple contributions calculations) calculations. The theoretical results revealed that the reaction takes place via an initial formation of a 1:1 complex of the two reactants, mainly driven by charge interaction, followed by an asynchronous concerted cyclization forming the 3H‐[1,2,4]‐triazolium ion 3, which undergo [1,2]‐H shift to provide the 1H‐[1,2,4]‐triazolium ion 4. The effect of the solvent has been modeled by using the isodensity‐surface polarizable continuum (IPCM) model and the calculation showed that the reaction in CH₂Cl₂ solution proceeds in a similar manner as in gas phase with only a slight derivation of activation barrier. The substituent effects have also been investigated. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

SYNTHESIS OF METAL- AND PENTEL-CONTAINING HETEROCYCLES USING NITRILES AND ISONITRILES

The reaction of benzylnitrile with InMe ₃ in a molar ratio of 3:1 leads to 2-amino-N-[Me ₂ In(TMEDA)]-4-amino-3,5-diphenyl-6-benzyl-pyridine 2. CsF accelerates the reaction. The treatment of Ph ₂ CHCN with InMe ₃ in the presence of CsF gives the metalated ketenimine [(THF)Me ₂ InNCCPh ₂ ] ₂ 3. 3 and the corresponding Ga compound also can be obtained by the metathesis reaction of Me ₂ MCl with LiNu═C═CPh ₂ . The attack of the Lewis bases ^t BuELi ₂ (E = P, As) on nitriles and isonitriles also leads to oligomerizations. ^t BuAsLi ₂ reacts with two molecules of PhCN to the aromatic heterocycle [AsNC(Ph)NC(Ph)]^? by forming the salt [Li(diglyme) ₂ ] [(TMEDA)Li([AsNC(Ph)NC(Ph)]) ₂ ] 4, while the reaction of ^t BuAsLi ₂ with three equivalents of ^c HexNC leads to the dilithium compound [{Li ₂ (diglyme)} ₂ { ^t BuAs(CN ^c Hex) ₃ } ₂ ] 5. Six molecules ^c HexNC were consumed when Li ₂ P ^t Bu was added to the isonitrile to give [{Li(DME)} ₂ { ^t BuP(CN ^c Hex) ₅ (CH)}] 6.     

A CONVENIENT SYNTHESIS OF NEW PYRIDOTHIENOPYRIMIDIN-4 (3H) ONES AND PYRIDOTHIENOPYRIMIDIN-2, 4(1H, 3H) DIONES

New derivatives of 2-substituted pyrido[3′,2′:4,5]thieno[3,2-d]pyri-midin-4(3H) ones and 3-substituted pyrido[3′,2′:4,5]thieno[3,2-d]pyri-midin-2,4(1H,3H) diones have been prepared by base catalyzed cyclocondensation of ethyl-3-aminothieno[3,2-b]pyridine-2-carboxylate with aryl nitriles and aryl- or alkyl isocyanates respectively.     

Novel Synthesis of Pyrido[2,1-B]Benzothiazoles and 1,3-Benzothiazole Derivatives

Abstract

A variety of new pyrido[2,1-b]benzothiazole and benzothiazoles, have been prepared via the reaction of 2-substituted methylthiazole with α,β-unsaturated nitriles and activated methylene compounds. The structures of the reaction products were established based on the elemental analyses and spectral data (IR, ¹H-, ¹³C-NMR, MS).