Alkylation of 2-methylimidazole with iodomethylsilanes

2-Methyl-1,3-bis[(1-methylsilolan-1-yl)methyl]-1H-imidazolium triiodide, 1,3-bis{[dimethyl-(phenyl)silyl]methyl}-2-methyl-1H-imidazolium iodide and triiodide, and cyclic 3,3,5,5,10-pentamethyl-4-oxa-7-aza-1-azonia-3,5-disilabicyclo[5.2.1]deca-1(10),8-diene iodide were synthesized by solvent-free reactions of 2-methyl-1H-imidazole with 1-(iodomethyl)-1-methylsilolane, (iodomethyl)(dimethyl)phenylsilane, and ethynyl(iodomethyl)(dimethyl)silanes, respectively, in the absence of base catalyst.     

Iodine-mediated ring-closing iodoamination with concomitant N-debenzylation for the asymmetric synthesis of polyhydroxylated pyrrolidines

Treatment of a range of homochiral unsaturated β-amino esters (containing a cis-dioxolane unit) with iodine promotes a novel ring-closing alkene iodoamination reaction which proceeds with concomitant N-debenzylation, providing a simple and stereoselective route to iodomethyl pyrrolidines. Functional group interconversion of the resulting iodomethyl pyrrolidines upon treatment with AgOAc proceeds via the corresponding aziridinium ion, with subsequent deprotection giving access to polyhydroxylated pyrrolidines.     

Alkylation of 4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-imidazole-2-thiol with iodomethylsilanes and -siloxanes

The alkylation of 4,5-dihydro-1H-imidazole-2-thiol with 1-iodomethyl(dimethyl)phenylsilane, 1-(iodomethyl)-1,1,3,3,3-pentamethyldisiloxane, and 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane involved iodine-catalyzed cleavage of the Si–C_sp ² and Si–O bonds with liberated (in situ) hydrogen iodide to afford 2-({[(4,5-dihydro-1H-imidazolium-2-ylsulfanyl)methyl]-1,1,3,3-tetramethyldisiloxanylmethyl}sulfanyl)-4,5-dihydro-1H-imidazolium di- and tetraiodides. Replacement of iodide ion in the products by triiodide gives new organosilicon ionic liquids with several charged fragments.     

(Iodomethyl)fluorosilanes: Synthesis and Reactions

The methods of synthesis of bifunctional (iodomethyl)fluorosilanes of general formula ICH₂SiMe_nF_3–n (n = 0, 2) have been elaborated; the structure was proved by ¹H, ¹³C, ²⁹Si NMR spectroscopy. The reaction of (iodomethyl)dimethylfluorosilane with O-trimethylsilyl derivative of N,N'-dimethylhydrazide of trifluoroacetic acid gives rise to the formation of 2,2,4,4-tetramethyl-6-(trifluoromethyl)-3,4-dihydro-2Н-1,4,5,2-oxadiasilin-4-ium iodide with tetracoordinate silicone atom.     

Novel design of 3,8-diazabicyclo[3.2.1]octane framework in oxidative sulfonamidation of 1,5-hexadiene

1,5-Hexadiene reacts with trifluoromethanesulfonamide in the oxidative system (t-BuOCl+NaI) to give trans-2,5-bis(iodomethyl)-1-(trifluoromethylsulfonyl)pyrrolidine 5 and 3,8-bis(trifluoromethylsulfonyl)-3,8-diazabicyclo[3.2.1]octane 6. With arenesulfonamides ArSO₂NH₂ (Ar=Ph, Tol), the reaction stops at the formation of the trans and cis isomers of 2,5-bis(iodomethyl)-1-(arenesulfonyl)pyrrolidine 7 and 8 (1:1). The cis isomers of 7 and 8 do not undergo cyclization to the corresponding 3,8-disubstituted 3,8-diazabicyclo[3.2.1]octanes. The reaction with triflamide represents the first example of one-pot two-step route to 3,8-diazabicyclo[3.2.1]octane system.     

Metallic samarium and iodine promoted facile and efficient syntheses of trisubstituted alkenes from the acetates of Baylis-Hillman adducts

Promoted by samarium metal in the presence of a catalytic amount of iodine, the Baylis-Hillman adducts underwent reductive elimination to form (E)-methylcinnamic ester derivatives. When the iodine was used in 1:1 ratio with metallic samarium, stereospecific syntheses of allylic iodide derivatives, (2Z)-2-(iodomethyl)alk-2-enoates, were achieved. Thus, this gives a new approach to the selective construction of stereo-defined trisubstituted alkenes with the simple Sm/I₂ system.     

An Improved Synthesis Route to Functionalized 2-Alkyn-1-ylboronates: Useful Intermediates for the Preparation of α-Allenic Alcohols

Summary. Functionalized 2-alkyn-1-ylboronates were successfully prepared in good yields by reacting various acyclic and cyclic (iodomethyl)boronates with various alkynyllithium salts. Amongst various (iodomethyl)boronates studied, 2-(iodomethyl)-1,3,2-dioxa-4,4,5,5-tetramethylborolane provided improved chemical yields of 2-alkyn-1-ylboronates with pyran- and triisopropylsilyl-substituted alkynyllithium salts. 2-Alkyn-1-ylboronate bearing an acid sensitive structure (pyran) was successfully synthesized which would be very difficult to achieve under previously reported reaction conditions. The exceptionally rapid rearrangement of the “ate” complex derived from the pinacol (iodomethyl)boronate, suppression of the side product formation, and the stability of the pinacol 2-alkyn-1-ylboronate are some of the notable merits of this protocol. This new procedure offers a simple and convenient alternative route to the existing methodologies, in terms of the milder reaction conditions, functional group compatibility, and the ease of the operation. The synthesis scope of this class of 2-alkyn-1-ylboronates was demonstrated by reacting the pinacol 2-alkyn-1-ylboronate with benzaldehyde, which yielded the α-allenic alcohol in good yield and regioselectivity.     

Facile formation of tetrahydrofurans with multiple chiral centers using double iodoetherification of σ-symmetric diene acetals: short asymmetric total synthesis of rubrenolide and rubrynolide

A novel double intramolecular iodoetherification of σ-symmetric diene acetals from (R,R)-hydrobenzoin occurred in highly diastereoselective manners to give tetrahydrofuran moieties with multiple chiral centers in a one-pot operation. The chemoselective discrimination of the two iodomethyl functions in the products was attained in various reactions. The reaction was applied to the concise asymmetric syntheses of rubrenolide and rubrynolide, in which the unit from the chiral auxiliary worked as a template to achieve the chemoselectivity and as the protecting group of the hydroxyl function.     

Mechanism of formation of macrocyclic siloxanes with a benzimidazole fragment by reaction of benzimidazole with 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane

The formation of macrocyclic polysiloxane system containing a benzimidazole fragment by reaction of benzimidazole with 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane was studied at the B3LYP/6-31G(d,p) level of theory. The calculations showed that expansion of siloxane ring involves thermodynamically controlled insertion of four silanone molecules generated by thermal decomposition of the complex derived from the initial siloxane and hydrogen triiodide.     

On the reaction of derivatives of bis(chloromethyl)phosphonic acid with potassium iodide

Conclusions The authors have obtained derivatives of (iodomethyl)(chloromethyl)- and bis(iodomethyl)phosphonic acids by reacting derivatives of bis(chloromethyl)phosphonic acid with KI.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1597–1598, July, 1967.     

Radical [3 + 2] cycloaddition reaction with various alkenes using iodomethylcyclopropane derivatives as new homoallyl radical precursors

Radical iodine atom transfer [3 + 2] cycloaddition with various alkenes using dimethyl 2-(iodomethyl)cyclopropane-1,1-dicarboxylate and 1,1-bis(phenylsulfonyl)-2-(iodomethyl)cyclopropane as new precursors of a homoallyl radical species smoothly proceeds to give functionalized cyclopentane derivatives in good yields.     

Conversion of a trans-syn-trans to a cis-syn-trans perhydrobenz[e]indenone triggered by intramolecular 1,5-hydrogen transfer

The conversion of a trans-syn-trans perhydroiodomethyltrimethylbenz[e]indenone to the corresponding cis-syn-trans perhydrobenz[e]indenone occurred during the reduction of the iodomethyl to a methyl group under radical conditions.     

Investigation of reaction between 2-methylimidazole and 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane by the method NALDI TOF/TOF

By the method of nanostructure-assisted laser desorption/ionization (NALDI) analysis was performed of solid and liquid fractions of reaction products formed from 2-methylimidazole and 1,3-bis- (iodomethyl)-1,1,3,3-tetramethyldisiloxane. Basing on the data post-source decay of iodides major and minor products of reaction were identified that were registered as ions [M–I]⁺ and [M–I₃]⁺.     

Quantum-chemical investigation of the reaction mechanism of 2-methylimidazole with 1,7-diiodo-2,2,6,6-tetramethyl-2,6-disilaheptane

Quantum-chemical investigation of the mechanism of reaction between 2-methylimidazole and 1,7-diiodo-2,2,6,6-tetramethyl-2,6-disilaheptane by the method B3LYP/6-311G(d,p) provided thermodynamic and kinetic characteristics of the formation channels of the new organosilicon fused and cyclophane structures whose yield depended on the ability of iodomethyl groups to be reduced at the action of HI formed in situ. On adding iodine that initiated the formation of triiodide anions the cyclic structures were stabilized as ionic liquids.     

Synthesis of new <Emphasis Type="Italic">N</Emphasis>-(pyridin-3-ylmethyl)-2-aminothiazoline derivatives possessing anticholinesterase and antiradical activity as potential multifunctional agents for the treatment of neurodegenerative diseases

New N-(pyridin-3-ylmethyl)-2-aminothiazolines containing various substituents at the 5 position of the thiazoline ring and the 4-tert-butylbenzyl, 4-isopropylbenzyl, or 4-fluorobenzyl moiety at the nitrogen atom of the amino group were synthesized. The inhibitory activity of the synthesized compounds against human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7), equine serum butyrylcholinesterase (BChE, EC 3.1.1.8), and porcine liver carboxylesterase (CaE, EC 3.1.1.1) was evaluated and their antioxidant properties were studied by ABTS assay. N-(Pyridin-3-ylmethyl)-2-aminothiazolines proveded to be very weak AChE inhibitors, while their inhibitory activity against BChE and CaE was structure-dependent. 2-Aminothiazolines containing the 4-tert-butylbenzyl moiety are more efficient BChE inhibitors compared to the derivatives containing the 4-isopropylbenzyl or 4-fluorobenzyl substituent. An analysis of the dependence of the esterase profile of N-(pyridin-3-ylmethyl)-2-aminothiazolines on the structure of the substituent at the 5 position of the thiazoline ring of these compounds demonstrated that the derivatives containing the iodomethyl substituent possess the highest anti-BChE activity, the compounds with R² = H and R³ = CH₂I have the optimal esterase profile. Regardless of the structure of the substituents in the benzyl moiety, all N-(pyridin-3-ylmethyl)-2-aminothiazolines containing the iodomethyl substituent at the 5 position of the thiazoline ring exhibited high radical scavenging activity comparable with that of the standard antioxidant Trolox. N-(Pyridin-3-ylmethyl)-2-aminothiazolines were shown to be a new promising class of compounds for the design of multifunctional agents for the treatment of neurodegenerative diseases.     

Alkylation of 1,2,3-benzotriazole with iodomethyl ketones

Solvent-free reactions of 1,2,3-benzotriazole with 1-iodopropan-2-one and 1,3-diiodopropan-2-one in the absence of a catalyst involved alkylation of the heteroring at the N¹ atom and subsequent quaternization at the N³ atom with formation of 1,3-bis(2-oxopropyl)-1H-1,2,3-benzotriazolium triiodide which is a new conducting ionic liquid. The reaction of 1,2,3-benzotriazole with 1,3-diiodopropan-2-one was accompanied by reductive deiodination of the iodomethyl groups in the initial ketone with hydrogen iodide liberated by N¹-alkylation. Triiodide ion readily exchanges for nitrate ion by the action of AgNO₃ to produce 1,3-bis(2-oxopropyl)-1H-1,2,3-benzotriazolium nitrate. The reaction of 1,2,3-benzotriazole with 2-iodo-1-phenylethan-1-one in melt resulted in the formation of 1,3-bis(2-oxo-2-phenylethyl)-1H-1,2,3-benzotriazolium triiodide.     

Synthesis of an adenine N-3 substituted CBI adduct by alkylation of adenine with a 1-iodomethylindoline seco-CBI precursor

The synthesis of a 1,2,9,9a-tetrahydrocyclopropa[c]benz[e]indol-4-one (CBI)-adenine adduct via regioselective N-3 alkylation of adenine with a 1-(iodomethyl)-2,3-dihydro-1H-benzo[e]indol-5-ol (I-seco-CBI)-containing precursor is described. Spectroscopic analyses of the unlabeled and adenine-C8 carbon-13 labeled adducts utilizing ROESY NMR techniques allowed structural assignment of the alkylation product as the adenine N-3 substituted regioisomer. A stable-isotopically labeled version of the N-3 adduct incorporating six carbon-13 labels was also prepared by this method for use as an LC-MS internal standard. The cyclized CBI-containing compound was also found to alkylate adenine at elevated temperatures to produce the N-3 adduct albeit at a significantly slower rate than that observed for the I-seco-CBI precursor. Adenine alkylation with an I-seco-CBI precursor offers scalable and facile access to a CBI-adenine adduct facilitating its use as an efficacy marker for the development of duocarmycin-based ADCs.     

Synthesis of β-Stannyl Esters

A synthesis of β-stannyl esters from ester enolates and iodomethyl (tri-n-butyl) stannane (3) is described.     

Synthesis of S- and S-S-Organosilicon Derivatives of 1,3-Benzothiazole-2-thiol

Russian Journal of Organic Chemistry - The reactions of 1,3-benzothiazole-2-thiol and di(1,3-benzothiazol-2-yl) disulfide with (iodomethyl)silanes containing exocyclic and endocyclic silicon atoms...     

Synthesis of Cycloprop[b]anthracenes via Trapping of o-Naphthoquinodimethane

Cycloprop[b]anthracenes 1, 1a, 1b are prepared in a 3-step synthesis starting from o-di(iodomethyl)benzene. The key step consists of trapping of o-naphthoquinodimethane (9) with 1,2-di- and tetrahalogenocyclopropenes (3, 3a, 4b) .