Reactions of β-nitrostyrenes with tert-butylmercury halides in the presence of lodide lon

Photolysis of t-BuHgCl/KI with PhC(R²)C(R¹)NO₂ forms PhC(R²)C(R¹)Bu-t when R¹ = R² = H or in low yield when R¹ = H, R² = Ph. When R¹ ≠ H, or when R² = Ph, reactions with t-BuHgI/KI/hv proceed mainly via PhC(R²)C(R¹)NO₂·-, PhC(R²)C(R¹)N(OBu-t)O⁻HgX⁺, PhC(R²)C(R¹)NO and PhC(R²)C(R¹)N(OBu-t)HgX to form a variety of novel products including the dimeric bisnitronic esters ( 6 ) with R¹ = Me or Ph and R² = H; PhCH(R²)C(R¹) = NOBu-t with R¹ = Me or Ph and R² = H or R¹ = H and R² = Ph; PhC(R²)(OBu-t)C(R¹)NOH with R¹ = H or Me and R² = Ph; and 3-phenyl-2-R¹-indoles with R¹ = H, Me, Ph, PhS or t-BuS and R² = Ph. Nitrosoaromatics react with t-BuHgX in the dark to form ArN(OBu-t)(OBu-t)HgX⁺ which condenses with ArNO to form the azoxy compound. tert-Butyl radicals will add to RNO₂ [R = Ph, Ph₂CCH, Ph₂CC(Ph)] in the presence of t-BuHgI₂⁻ to form products derived from RN(OBu-t)O⁻HgI⁺.     

Naphthalene Exchange in [Re(η6-napht)2]+ with Pharmaceuticals Leads to Highly Functionalized Sandwich Complexes [M(η6-pharm)2]+ (M=Re/99mTc)

Bis-arene sandwich complexes are generally prepared by the Fischer-Hafner reaction, which conditions are incompatible with most O- and N- functional groups. We report a new way for the synthesis of sandwich type complexes [Re(η⁶-arene)₂]⁺ and [Re(η⁶-arene)(η⁶-benzene)]⁺ from [Re(η⁶-napht)₂]⁺ and [Re(η⁶-napht)(η⁶-benzene)]⁺, with functionalized arenes and pharmaceuticals. N-methylpyrrolidine (NMP) facilitates the substitution of naphthalene with the incoming arene. A series of fully characterized rhenium sandwich complexes with simple arenes, such as aniline, as well as with active compounds like lidocaine and melatonin are presented. With these rhenium compounds in hand, the radioactive sandwich complexes [^99mTc(η⁶-pharm)₂]⁺ (pharm=pharmaceutical) can be unambiguously confirmed. The direct labelling of pharmaceuticals with ^99mTc through η⁶-coordination to phenyl rings and the confirmation of the structures with the rhenium homologues opens a path into molecular theranostics.     

Syntheses of diaza-18-crown-6 ligands containing two units each of 4-hydroxyazobenzene,benzimidazole, uracil,anthraquinone, or ferrocene groups

Six new diaza-18-crown-6 ligands each containing two aromatic side arms with responsive functions were prepared. Diaza-18-crown-6 containing two 4-hydroxyazobenzene ( 3 ) or two 4 -hydroxy- 4′ -(dimethyl-amino)azobenzene ( 4 ) substituents were prepared via a one-pot Mannich reaction. Diaza-18-crown-6 containing two benzimidazole ( 5 ), two uracil ( 6 ) or two 9,10-anthraquinone ( 7 ) substituents were prepared by treating the diazacrown with the appropriate chloromethyl-containing compound. Reductive amination using sodium triacetoxyborohydride, diaza-18-crown-6 and ferrocenecarboxaldehyde was used to prepare bisferrocene-substituted diaza-18-crown-6 ( 8 ). Interactions of compounds 3 , 5 , and 6 with Na⁺, K⁺, Ba²⁺, Ag⁺, and Cu²⁺ were evaluated by a calorimetric titration technique at 25° in methanol. All three ligands form more stable complexes with Ag⁺ and Cu²⁺ ( 5 forms a precipitate with Ag⁺) than with Na⁺ and K⁺. Ligand 5 also forms a highly stable complex with Ba²⁺.     

Cross sections for fast-neutron interaction with erbium isotopes

Cross-sections for (n,2n), (n,p), (n,α), and (n,d*) (The expression (n,d*) cross section used in this work includes a sum of (n, d), (n, np) and (n, pn) cross sections) reactions have been measured on erbium isotopes at the neutron energies from 13.5 to 14.8 MeV using the activation technique in combination with high-resolution gamma-ray spectroscopy. Data are reported for the following reactions: ¹⁶²Er(n,2n)¹⁶¹Er, ¹⁶⁴Er(n,2n)¹⁶³Er, ¹⁶⁸Er(n,α)^165mDy, ¹⁶⁶Er(n,p)^166gHo, ¹⁷⁰Er(n,α)¹⁶⁷Dy, ¹⁶⁸Er(n,p)^168m+gHo, ¹⁷⁰Er(n,p)^170gHo, and ¹⁷⁰Er(n,d*)¹⁶⁹Ho. The cross sections were discussed and compared with experimental data found in the literature, and with the comprehensive evaluation data in ENDF/B-VII.0 and l JEFF-3.1/A libraries.     

Independent isomeric-yield ratio of 89m,gNb from 93Nb(γ, 4n), natZr(p,xn), and 89Y(α, 4n) reactions

The independent isomeric-yield ratios of ^89m,gNb for the ⁹³Nb(γ, 4n) ^89m,gNb reaction with bremsstrahlung energies of 45-, 50-, 55-, 60-, and 70-MeV were measured by the activation and the off-line γ-ray spectrometric technique at 100 MeV electron linac of the Pohang accelerator laboratory. The isomeric-yield ratios of ^89m,gNb for the ^natZr(p, xn) ^89m,gNb and the ⁸⁹Y(α, 4n) ^89m,gNb reactions were measured by using a stacked-foil activation technique with the proton energies of 19–45 MeV and alpha energies of 38.9-, 40.5-, and 42.5-MeV at the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured isomeric-yield ratio of ^89m,gNb from the ⁹³Nb(γ, 4n), ^natZr(p, xn), and ⁸⁹Y(α, 4n) reactions were compared with the similar literature data in the ⁸⁹Y(³He, 3n) reaction. It was found that the isomeric yield ratio of ^89m,gNb increases with projectile energy, which indicate the effect of excitation energy. However, for the similar compound nucleus with the same excitation energy, the isomeric-yield ratios of ^89m,gNb in the ⁸⁹Y(α, 4n) and ⁸⁹Y(³He, 3n) reactions are higher than those in the ⁹³Nb(γ, 4n) and ^natZr(p, xn) reactions, which indicates the role of input angular momentum. The isomeric-yield ratios of ^89m,gNb in the ⁹³Nb(γ, 4n), ^natZr(p, xn), ⁸⁹Y(α, 4n), and ⁸⁹Y(³He, 3n) reactions were also calculated theoretically using computer code TALYS 1.4. The theoretical isomeric-yield ratios of ^89m,gNb from four reactions increase with excitation energy. However, the theoretical value are significantly higher than the experimental data in the ⁹³Nb(γ, 4n) and ^natZr(p, xn) reactions but slightly lower or comparable in the ⁸⁹Y(α, 4n) rand ⁸⁹Y(³He, 3n) reactions.     

Activation of small molecules by a rhodium bis(phosphinite) pincer complex

Rhodium hydrido chloride pincer complex RhH(Cl)[2,6-(Bu^{pt b2}PO)^b2C^b6H^b3] was synthesized and used for the preparation of new complexes with labile two-electron ligands Rh(L)[2,6-(Bu^{pt b2}PO)^b2C^b6H^b3] (L = MeCN or S(CH^b2)^b4) and complexes with small molecules, such as CO, O^b2, H^b2, and N^b2.     

Dynamic study of photosensitized one-electron oxidation of polyG by menadione

Quinones including menadione are ubiquitous in nature. They play important roles in aerobic respira- tion and photosynthesis[1,2]. In addition, exogenous quinones are used as antibiotics and anticancer drugs. Their function is closely related to their red…     

Structures of Metal Complexes with Anions of Di(hydroxymethyl)phosphinic and Di(chloromethyl)phosphinic Acids

This paper considers the structural features of complexes containing Ag(I), 3dmetals (Cu and Ni), and rare-earth elements (REE) such as La, Nd, Er, and Lu, alkaline-earth (Sr) or alkaline (Li, Na) metals with anions of di(hydroxymethyl)phosphinic (L¹) or di(chloromethyl)phosphinic (L²) acids with a general formula RR"PO^– ₂, where R = R" = OH and Cl for L¹and L², respectively. Different patterns of coordination between organophosphorus acids and different metals (four for each L¹and L²) are described. Structures of copper(II) complexes with L¹and L²were compared with those of Cu(II) with dialkyl- and diaryl-substituted monophosphonic and aminophosphinic acids.     

Measurement of the neutron capture cross-section of 238U using the neutron activation technique

The ²³⁸U(n, ??)²³⁹U reaction cross-section at average neutron energy of 3.7?±?0.3?MeV from the ⁷Li(p, n)⁷Be reaction has been determined using activation and off-line ??-ray spectrometric technique. The ²³⁸U(n, ??)²³⁹U and ²³⁸U(n, 2n)²³⁷U reaction cross-sections at average neutron energy of 9.85?±?0.38?MeV from the same ⁷Li(p, n)⁷Be reaction have been also determined using the above technique. The experimentally determined ²³⁸U(n, ??)²³⁹U and ²³⁸U(n, 2n)²³⁷U reaction cross-sections were compared with the evaluated data of ENDF/B-VII, JENDL-4.0, JEFF-3.1 and CENDL-3.1. The experimental values were found to be in general agreement with the evaluated value based on ENDF/B-VII, and JENDL-4.0 but not with the JEFF-3.1 and CENDL-3.1. The present data along with literature data in a wide range of neutron energies were interpreted in terms of competition between different reaction channels including fission. The ²³⁸U(n, ??)²³⁹U and ²³⁸U(n, 2n)²³⁷U reaction cross-sections were also calculated theoretically using the TALYS 1.2 computer code and were also found to be in agreement experimental data.     

Kinetics and mechanisms of the reactions of aluminium(III) with β-diketones in aqueous solution

The kinetics and mechanisms of the reactions of aluminium(III) with pentane-2,4-dione (Hpd), 1,1,1-trifluoro pentane-2,4-dione (Htfpd) and heptane-3,5-dione (Hhptd) have been investigated in aqueous solution at 25°C and ionic strength 0.5 mol dm⁻³ sodium perchlorate. The kinetic data are consistent with a mechanism in which aluminium(III) reacts with the β-diketones by two pathways, one of which is acid independent while the second exhibits a second-order inverse-acid dependence. The acid-independent pathway is ascribed to a mechanism in which [Al(H₂O)₆]³⁺ reacts with the enol tautomers of Hpd, Htfpd, and Hhptd with rate constants of 1.7(±1.3)×10⁻², 0.79(±0.21), and 7.5(±1.6)×10⁻³ dm³ mol⁻¹ s⁻¹, respectively. The inverse acid pathway is consistent with a mechanism in which [Al(H₂O)₅(OH)]²⁺ reacts with the enolate ions of Hpd, Htfpd, and Hhptd with rate constants of 4.32(±0.18)×10⁶, 5.84(±0.24)×10³, and 1.67(±0.05)×10⁷ dm³ mol⁻¹ s⁻¹, respectively. An alternative formulation involves a pathway in which [Al(H₂O)₄(OH)₂]⁺ reacts with the protonated enol tautomers of the ligands. This gives rate constants of 2.79(±0.12)×10⁴, 3.86(±0.16)×10⁵, and 8.98(±0.25)×10³ dm³ mol⁻¹ s⁻¹ for reaction with Hpd, Htfpd, and Hhptd, respectively. Consideration of the kinetic data reported here together with data from the literature, suggest that [Al(H₂O)₅(OH)]²⁺ reacts by an associative or associative-interchange mechanism. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 257–266, 1998.     

Complexation of Ni(II) with Benzoic,p-Methoxybenzoic,and Isonicotinic Acids Hydrazides in Aqueous Acetonitrile

Solvation and complexation of Ni(II) with benzoic (L¹), p-methoxybenzoic (L³), and isonicotinic (L) acids hydrazides in water and aqueous acetonitrile were studied. The coordination of acetonitrile with Ni(II) was qualitatively estimated, and the formation constant were determined for the complexes Ni(L¹)^{2 +}, Ni(L¹)2^{2 +}, Ni(L³)^{2 +}, Ni(L³)2^{2 +}, Ni(HL)^{3 +}, NiL^{2 +}, NiL(HL)^{3 +}, and NiL₂ ^{2 +}. The effects of dilution, ligand basicity, and ligand solvation on the stability of Ni(II) compounds with hydrazides of benzoic acid and its derivatives were demonstrated. The stability of the Ni(II) complexes with isonicotinic acid hydrazide is governed by dehydration of the metal ion, decrease in the donor power of the coordinating hydrazide fragment on protonation of the pyridine substituent L, formation of the intracomplex hydrogen bond between the protonated and deprotonated pyridine nitrogen atoms in NiL(HL)^{3 +}, and stacking interaction between the heterocycles in NiL₂ ^{2 +}.     

The development of nuclear microprobe techniques for the spatial determination of13C and13C/12C ratios

Sensitive and selective nuclear reaction methods have been sought for the nuclear microprobe measurement of the spatial distributions of¹³C and¹³C/¹²C ratios. The¹³C(α, n)¹⁶O reaction, with neutron detection, is the most selective for¹³C, and has a sensitivity of ca. 100 ppm. The reactions¹³C(d, p)¹⁴C and¹²C(d, p)¹³C, with proton detection, are the most sensitive for the simultaneous measurement of¹³C and¹²C, with detection limits of 30 and 2 ppm respectively. Less sensitive alternative reaction pairs are;¹³C(³He, p)¹⁵N and¹²C(³He, p)¹⁴N;¹³C(d, nγ)¹⁴N and¹²C(d, pγ)¹³C;¹³C(³He, pγ)¹⁵N and¹²C(³He, pγ)¹⁴N. The conditions governing their use, particularly light element interferences, are detailed.     

Atranes

Genetal methods are described for the preparation of metalloatrane-3,7,10-triones, containing an atom of a ter-, quarter-, or quinquevalent metal (mainly in the form of hydrates). Seven intramolecular compounds of this type (with M = Nd^III, ClTi^IV, ClZr^IV, Ce^III, HOPb^IV, HOMn^IV, HOOU^VI), have been prepared, of which only two (with M = Nd^III and HOOU^VI) were known previously. Compounds with the composition N (CH₂COO)₃M · mN (CH₂COO)₃ · nH₂O with M = Nd^III, Th^IV, CO^III and Ni^III (m=1) and with M = Sb (m=3 and 4) have also been obtained.For part XVIII, see [1].     

Reactive regioregular oligothiophenes and polythiophenes with Zincke salt structure: Synthesis,reactions, and chemical properties

Polythiophenes with reactive Zincke salt structure, P4ThPy⁺DNP(Cl^?)‐a and P5ThPy⁺DNP(Cl^?)‐a , were synthesized by the oxidation polymerization of oligothiophenes, such as 3'‐(4‐N‐(2,4‐dinitrophenyl)pyridinium chloride)?2,2':5',2'';5'',2'''‐quarterthiophene ( 4ThPy⁺DNP(Cl^?) ) and 4''‐(4‐N‐(2,4‐dinitrophenyl)pyridinium chloride)?2,2';5',2'';5'',2''';5''',2''''‐quinquethiophene ( 5ThPy⁺DNP(Cl^?) ), with iron(III) chloride. The reaction of P5ThPy⁺DNP(Cl^?)‐a with R‐NH₂ [R = n‐hexyl (Hex) and phenyl (Ph)] substituted the 2,4‐dinitrophenyl group into the R group with the elimination of 2,4‐dinitroaniline to yield P5ThPy⁺R(Cl^?) . Similarly, model compounds, 4ThPy⁺R(Cl^?) and 5ThPy⁺R(Cl^?) (R = Hex and Ph), were also synthesized. In contrast to the photoluminescent 4ThPy and 5ThPy , the compounds P4ThPy⁺DNP(Cl^?)‐a , P5ThPy⁺DNP(Cl^?)‐a , and P5ThPy⁺R(Cl^?) showed no photoluminescence because their internal pyridinium rings acted as quenchers. Cyclic voltammetry measurements suggested that P4ThPy⁺DNP(Cl^?)‐a , P5ThPy⁺DNP(Cl^?)‐a , and P5ThPy⁺R(Cl^?) received an electrochemical reduction of the pyridinium and 2,4‐dinitrophenyl groups and oxidation of the polymer backbone. P4ThPy⁺DNP(Cl^?)‐a and P5ThPy⁺DNP(Cl^?)‐a were electrically conductive (ρ = 3.0 × 10 ^{? 6} S cm ^{? 1} and 2.1 × 10 ^{? 6} S cm ^{? 1}, respectively) in the nondoped state. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 481–492     

2′,4′-BNA/LNA with 9-(2-Aminoethoxy)-1,3-diaza-2-oxophenoxazine Efficiently Forms Duplexes and Has Enhanced Enzymatic Resistance**

Artificial nucleic acids are widely used in various technologies, such as nucleic acid therapeutics and DNA nanotechnologies requiring excellent duplex-forming abilities and enhanced nuclease resistance. 2′-O,4′-C-Methylene-bridged nucleic acid/locked nucleic acid (2′,4′-BNA/LNA) with 1,3-diaza-2-oxophenoxazine (BNAP ( B^H )) was previously reported. Herein, a novel B^H analogue, 2′,4′-BNA/LNA with 9-(2-aminoethoxy)-1,3-diaza-2-oxophenoxazine (G-clamp), named BNAP-AEO ( B^AEO ), was designed. The B^AEO nucleoside was successfully synthesized and incorporated into oligodeoxynucleotides (ODNs). ODNs containing B^AEO possessed up to 10⁴-, 152-, and 11-fold higher binding affinities for complementary (c) RNA than those of ODNs containing 2′-deoxycytidine ( C ), 2′,4′-BNA/LNA with 5-methylcytosine ( L ), or 2′-deoxyribonucleoside with G-clamp ( P^AEO ), respectively. Moreover, duplexes formed by ODN bearing B^AEO with cDNA and cRNA were thermally stable, even under molecular crowding conditions induced by the addition of polyethylene glycol. Furthermore, ODN bearing B^AEO was more resistant to 3′-exonuclease than ODNs with phosphorothioate linkages.     

Ferrate(VI) and ferrate(V) oxidation of cyanide,thiocyanate, and copper(I) cyanide

Cyanide (CN⁻), thiocyanate (SCN⁻), and copper(I) cyanide (Cu(CN)₄³⁻) are common constituents in the wastes of many industrial processes such as metal finishing and gold mining, and their treatment is required before the safe discharge of effluent. The oxidation of CN⁻, SCN⁻, and Cu(CN)₄³⁻ by ferrate(VI) (Fe^VIO₄²⁻; Fe(VI)) and ferrate(V) (Fe^VO₄³⁻; Fe(V)) has been studied using stopped-flow and premix pulse radiolysis techniques. The rate laws for the oxidation of cyanides were found to be first-order with respect to each reactant. The second-order rate constants decreased with increasing pH because the deprotonated species, FeO₄²⁻, is less reactive than the protonated Fe(VI) species, HFeO₄⁻. Cyanides react 10³–10⁵ times faster with Fe(V) than with Fe(VI). The Fe(V) reaction with CN⁻ proceeds by sequential one-electron reductions from Fe(V) to Fe(IV) to Fe(III). However, a two-electron transfer process from Fe(V) to Fe(III) occurs in the reaction of Fe(V) with SCN⁻ and Cu(CN)₄³⁻. The toxic CN⁻ species of cyanide wastes is converted into relatively non-toxic cyanate (NCO⁻). Results indicate that Fe(VI) is highly efficient in removing cyanides from electroplating rinse water and gold mill effluent.     

A kinetic study of the reduction of toluidine blue with thiourea in acidic solution

A detailed kinetic study of the reaction of toluidine blue (tolonium chloride) (TB⁺ Cl^?) with thiourea (TU) in aqueous hydrochloric acid solution is reported. The reaction was first order with respect to toluidine blue and the reductant and second order with respect to [H⁺]. Thiourea had a 2:1 stoichiometric ratio with TB⁺. Toluidine blue was reduced to a colorless base in two one-electron reduction steps and TU was oxidized to thioformamidinium ion, which dimerized rapidly to give stable dithioformamidinium ion. The energy parameters obtained for TB⁺-TU reaction were mean energy of activation (Ea′) = 26.7 ± 2.4 kJ M^?1; enthalpy of activation (ΔH^#) = 24.2 kJ M^?1; frequency factor (A) = 1.04 × 10⁴ M^?3 s^?1; and entropy of activation (ΔS^#) = ?176.35 J M^?1 s^?1. © John Wiley & Sons, Inc.     

Radical Anions,Radical-Anion Salts,and Anionic Complexes of 2,1,3-Benzochalcogenadiazoles

By means of cyclic voltammetry (CV) and DFT calculations, it was found that the electron-acceptor ability of 2,1,3-benzochalcogenadiazoles 1 – 3 (chalcogen: S, Se, and Te, respectively) increases with increasing atomic number of the chalcogen. This trend is nontrivial, since it contradicts the electronegativity and atomic electron affinity of the chalcogens. In contrast to radical anions (RAs) [ 1 ]^.− and [ 2 ]^.−, RA [ 3 ]^.− was not detected by EPR spectroscopy under CV conditions. Chemical reduction of 1 – 3 was performed and new thermally stable RA salts [K(THF)]⁺[ 2 ]^.− ( 8 ) and [K(18-crown-6)]⁺[ 2 ]^.− ( 9 ) were isolated in addition to known salt [K(THF)]⁺[ 1 ]^.− ( 7 ). On contact with air, RAs [ 1 ]^.− and [ 2 ]^.− underwent fast decomposition in solution with the formation of anions [ECN]⁻, which were isolated in the form of salts [K(18-crown-6)]⁺[ECN]⁻ ( 10 , E=S; 11 , E=Se). In the case of 3 , RA [ 3 ]^.− was detected by EPR spectroscopy as the first representative of tellurium–nitrogen π-heterocyclic RAs but not isolated. Instead, salt [K(18-crown-6)]⁺₂[ 3 -Te₂]²⁻ ( 12 ) featuring a new anionic complex with coordinate Te−Te bond was obtained. On contact with air, salt 12 transformed into salt [K(18-crown-6)]⁺₂[ 3 -Te₄- 3 ]²⁻ ( 13 ) containing an anionic complex with two coordinate Te−Te bonds. The structures of 8 – 13 were confirmed by XRD, and the nature of the Te−Te coordinate bond in [ 3 -Te₂]²⁻ and [ 3 -Te₄- 3 ]²⁻ was studied by DFT calculations and QTAIM analysis.     

Reactive polythiophenes with zincke salt structure: Synthesis,polymer reactions,and chemical properties

Polythiophenes with reactive Zincke salt structure, such as PThThPy⁺DNP(Cl^?)Th , were synthesized by the oxidation polymerization of 3′‐(4‐N‐(2,4‐dinitrophenyl)pyridinium chloride)‐2,2′:5′,2″‐terthiophene ( ThThPy⁺DNP(Cl^?)Th ) with iron(III) chloride or copper(II) trifluoromethanesulfonate. The reaction of PThThPy⁺DNP(Cl^?)Th with R‐NH₂ (R = n‐hexyl (Hex) and phenyl (Ph)) substituted the 2,4‐dinitrophenyl group into the R group with the elimination of 2,4‐dinitroaniline to yield PThThPy⁺R(Cl^?)Th . Similarly, model compounds, ThThPy⁺R(Cl^?)Th (R = Hex and Ph), were also synthesized. In contrast to the photoluminescent ThThPyTh and PThThPyTh , the compounds PThThPy⁺DNP(Cl^?)Th , PThThPy⁺R(Cl^?)Th , and ThThPy⁺R(Cl^?)Th showed no photoluminescence because their internal pyridinium rings acted as quenchers. Cyclic voltammetry measurements suggested that PThThPy⁺DNP(Cl^?)Th received an electrochemical reduction of the pyridinium and 2,4‐dinitrophenyl groups and oxidation of the polymer backbone. PThThPy⁺DNP(Cl^?)Th was electrically conductive (ρ = 2.0 × 10^?6 S cm^?1) in the non‐doped state. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

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.