Selective n,n-dimethylation of primary aromatic amines with methyl alkyl carbonates in the presence of phosphonium salts

In the presence of onium salts, at 140-170 degrees C, methyl alkyl carbonates [1a-c, ROCO2Me, R = MeO(CH2)2[O(CH2)2]n; n = 2-0, respectively] react with primary aromatic amines (XC6H4NH2, X= p-OMe, p-Me, H, p-Cl, p-CO2Me, o-Et, and 2,3-Me2C6H3NH2) to yield the corresponding N,N-dimethyl derivatives (ArNMe2) with high selectivity (up to 96%) and good isolated yields (78-95%). Phosphonium salts (e.g., Ph3PEtI and n-Bu4PBr) are particularly efficient catalysts. Overall, a solvent-free reaction is coupled with safe methylating agents (1a-c) made from nontoxic dimethyl carbonate.     

Pd(OAc)2-catalyzed carbonylation of amines

A phosphine-free catalytic system [Pd(OAc)2-Cu(OAc)2-air] induced a substrate-specific carbonylation of amines in boiling toluene under CO gas (1 atm). Symmetrical N,N'-dialkylureas were obtained by the carbonylation of primary amines. N,N,N'-Trialkylureas were selectively formed by addition of a secondary amine to the above reaction vessel. Secondary amines did not give tetraalkylureas. However, dialkylamines with a phenyl group on their alkyl chains, such as N-monoalkylated benzylic amine or phenethylamine derivatives, underwent a direct aromatic carbonylation to afford five- or six-membered benzolactams. In the carbonylation, the chelation effect or steric repulsion between Pd(II) and the meta-substituent in the ortho-palladation and the ring sizes of cyclopalladation products that were formed prior to carbonylation were found to generate good site selectivity and increase the reaction rate. In contrast, carbonylation of omega-arylalkylamines with a hydroxyl group gave neither ureas nor benzolactams but instead produced 1,3-oxazolidinones smoothly. Hydrochlorides of amines also underwent carbonylation to afford the corresponding amides under the conditions used. This procedure made it possible to prepare ureas of amino acid esters and N-alkylcarbamates in practical yields.     

Selective and environmentally friendly methodologies based on the use of electrochemistry for fine chemical preparation: an efficient synthesis of N,N'-disubstituted ureas

A novel efficient synthesis of N,N'-disubstituted ureas has been developed. Aromatic and aliphatic primary amines undergo oxidative carbonylation under atmospheric pressure of carbon monoxide using Pd(II) catalyst in combination with its anodic recycling at a graphite electrode.     

常温常压下光促进烯烃与一氧化碳的羰基化反应

 报道了烯烃（环己烯和1－辛烯）与一氧化碳通过光促进实现常温常压非贵金属（钴配合物）催化的羰基化反应．研究发现，以Co（OAc）2为催化剂时，不需要加入光敏剂丙酮就能发生反应；CoSalen，吡啶－2－羧酸钴和大环配合物［Co（14）4，11－diene－N4］I2是较好的催化剂，其催化活性比Co（OAc）2高．其中，吡啶－2－羧酸钴与Co（OAc）2相同，反应中不需要光敏剂存在，其选择性很高．通过氘代丙酮和氘代甲醇同位素实验，进一步证实了反应中双键异构的存在和副产物的分析结果．     

N‐Heterocyclic Carbene–Palladium Complexes as Efficient Catalysts for the Oxidative Carbonylation of Amines to Ureas

A highly efficient oxidative carbonylation reaction of amines to ureas was developed making use of carbene–palladium complexes in the absence of any promoter. Both aliphatic amines and aromatic amines were transformed in good to excellent yields to the expected ureas.     

Copper-mediated imine-nitrile coupling leading to unsymmetric 1,3,5-triazapentadienato complexes containing the incorporated iminoisoindolin-1-one moiety

The copper(II)-mediated integration between various 3-iminoisoindolin-1-ones and neat organonitriles (which play a dual role of solvent and reactant), under heating for ca. 12 h, and without requiring any base, accomplishes the release of the solid (1,3,5-triazapentadienato)Cu(II) complexes [Cu{HN=C(R)N=C(C(6)R(1)R(2)R(3)R(4)CO)N}(2)] (1-11) bearing the incorporated iminoisoindolin-1-one fragment. These compounds were isolated in moderate to good yields (44-78%) and do not require further purification. The iminoisoindolinone-nitrile coupling is Cu(II)-mediated and has a general character insofar as it can be efficiently applied for both unsubstituted (R(1)-R(4) = H) and substituted iminoisoindolin-1-ones (R(1), R(3), R(4) = H, R(2) = Me; R(1), R(4) = H, R(2), R(3) = Cl; R(1)-R(4) = F), and a wide range of nitriles (R = Me, Et, Pr(n), Pr(i), C(6)H(11), CH(2)Ph). Complexes 1-11 were characterized by elemental analyses (C, H, N), FAB(+)-MS, IR spectroscopy, and additionally compounds 1, 2 and 4 by single-crystal X-ray diffraction.     

2-硒代咪唑类化合物催化CO与胺的羰基化反应

首次研究了2-硒代咪唑类化合物催化的一氧化碳对胺的羰基化生成对称脲或噁唑啉-2-酮的反应,目标产物收率中等到良好.与传统的单质硒催化的羰基化反应相比,新催化体系有效避免了有恶臭气味的含硒化合物的产生.     

硒催化的乙二胺、乙醇胺和环胺的氧化羰基化反应

研究了以硒粉作催化剂,一氧化碳为羰基化试剂的乙二胺、乙醇胺和一些环胺的羰基化反应,考察了氧化剂对反应的影响。发现氧气是该反应较好的氧化剂,而没有氧化剂存在时,几乎没有羰基化反应发生。在硒／氧化剂体系存在下,乙二胺和乙醇胺这样一些分子内具有相邻两个亲基团物质的羰基化反应易趋向于分子内羰基化形成较为稳定的五元环产物,产率和选择性较高;而环胺如哌啶和吗啡啉的羰基化可生成相应的四取代脲产物。对反应机理进行     

非对称取代脲的合成与应用

总结了合成非对称取代脲的几种方法，分析了各种方法的利弊，介绍了非对称 取代脲的主要应用，指出直接利用一氧化碳进行硒催化的胺与硝基化合物的氧化还 原羰基化反应来合成非对称取代脲的方法是比较有发展前景的方法，并对硒催化的 氧化还原羰基化反应作了较为详细的介绍。     

钯催化芳基偶氮的氧化羰基化反应

采用TBHP作为氧化剂,发展了钯催化芳基偶氮化合物N＝N双键断裂的氧化羰基化反应.芳基偶氮的羰基化反应在Pd(OAc)2(5％),MeO-BIPHEP (5％),芳基偶氮(0.2 mmol),TBHP(2 equiv),H2O(1 equiv),DCE(1 mL),CO (3.0 MPa)的条件下110℃反应12h后,经柱层析纯化分离得到31％-91％的芳基脲.初步的机理研究表明,芳基偶氮化合物的N＝N双键断裂原位产生芳基胺,再进一步氧化羰基化生成芳基脲.     

Electron-transfer-catalyzed rearrangement of unsymmetrically substituted diiron dithiolate complexes related to the active site of the [FeFe]-hydrogenases

Novel asymmetrically substituted azadithiolate compounds [Fe2(CO)4(kappa2-dppe){micro-SCH2N(R)CH2S}] (R=iPr, 1a; CH2CH2OCH3, 1b; CH2C6H5, 1c) have been synthesized by treatment of [Fe2(CO)6(micro-adt)] [adt=SCH2N(R)CH2S, with R=iPr, CH2CH2OCH3, CH2C6H5] with dppe (dppe=Ph2PCH2CH2PPh2) in refluxing toluene in the presence of Me3NO. 1a-c have been characterized by single-crystal X-ray diffraction analyses. The electrochemical investigation of 1a-c and of [Fe2(CO)4(kappa2-dppe)(micro-pdt)] (1d) [pdt=S(CH2)3S] in MeCN- and THF-[NBu4][PF6] has demonstrated that the electrochemical reduction of 1a-d gives rise to an Electron-transfer-catalyzed (ETC) isomerization to the symmetrical isomers 2a-d where the dppe ligand bridges the iron centers. Compounds 2a-d were characterized by IR and NMR spectroscopy, elemental analysis, and X-ray crystallography for 2a.     

Nitrogen-containing organobases as promoters in the cobalt(II)-Schiff base catalyzed oxidative carbonylation of amines

The use of organic bases as promoters in the cobalt(II)-Schiff base complex catalyzed oxidative carbonylation of amines was investigated. The generality of the reaction was also studied by submitting different amines to the same procedure and by changing the reaction conditions. Very good yields in the corresponding ureas were achieved in toluene with a catalyst loading of 0.5 mol % and using TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) as promoter. Methyl carbamates were obtained in methanol.     

Stereospecific synthesis of polysubstituted E-olefins by reaction of acyclic nitrones with free and platinum(II) coordinated organonitriles

Free nitriles NCCH2R (1a R = CO2Me, 1b R = SO2Ph, and 1c R = COPh) with an acidic alpha-methylene react with acyclic nitrones -O+N(Me)=C(H)R' (2a R' = 4-MeC6H4 and 2b R' = 2,4,6-Me3C6H2), in refluxing CH2Cl2, to afford stereoselectively the E-olefins (NC)(R)C=C(H)R' (3a-3c and 3a'-3c'), whereas, when coordinated at the platinum(II) trans-[PtCl2(NCCH2R)2] complexes (4a R = CO2Me and 4b R = Cl), they undergo cycloaddition to give the (oxadiazoline)-PtII complexes trans-[PtCl2{N=C(CH2R)ON(Me)C(H)R'}2] (R = CO2Me, Cl and R' = 4-MeC6H4, 2,4,6-Me3C6H2) (5a-5d). Upon heating in CH2Cl2, 5a affords the corresponding alkene 3a. The reactions are greatly accelerated when carried out under focused microwave irradiation, particularly in the solid phase (SiO2), without solvent, a substantial increase of the yields being also observed. The compounds were characterized by IR and 1H, 13C, and 195Pt NMR spectroscopies, FAB+-MS, elemental analyses and, in the cases of the alkene (NC)(CO2Me)C=C(H)(4-MeC6H4) 3a and of the oxadiazoline complex trans-[PtCl2{N=C(CH2Cl)ON(Me)C(H)(4-C6H4Me)}2] 5c, also by X-ray diffraction analyses.     

Acyl-lithiation of olefins: formation of cyclopentenones from 1-lithio-butadienes and CO

[reaction: see text] Intramolecular acyl-lithiation of C=C double bonds proceeds following carbonylation of 1-lithio-1,3-dienes with CO to afford 2- or 3-cyclopentenone derivatives in good to excellent yields after hydrolysis. Addition of electrophiles to the carbonylation reaction mixtures affords various multiply substituted cyclopentenones.     

Bioisostere of Sulfonyl Moiety-The Synthesis of New ALS Inhibitors N-(Asymmetry Disubstituted Phosphoryl)-N'-(4,6-dimethoxypyrimidin-2-yl) Ureas

IntroductionAcetolactatesynthase(ALS)isthefirstcommonenzymeinthebiosyntheticpathwayforthebranched-chainaminoacidsvaline,leucineandisoleucine.Itisaveryeffectivetargetsiteforherbicidalaction,whichistheselectedmodeofactionasitisspecificforplantsanddoesnotaffectmammals.Sulfonylureaherbicidesareanewclassofherbicidesdiscoveredinthemid-l97O'sl.ItsmodeofactionhasbeenestablishedtobeinhibitorytowardALS2.Muchattentionhasbeenfocusedonthiskindofcompounds,sincetheyhaveexcellentactivity,ahighdegreeofseIe…     

三烃基锡β-2, 8, 9-三氧杂-5-氮杂-1-锗杂三环[3.3.3.0^1.5]十一碳烷基(β-取代)丙酸酯的研究

本文合成了15个含锡锗杂恶唑烷化合物,N(CH~2CH~2O)~3GeCHR^1CH~2CO~2SnR(R=Cy~3, Bu~3^n, Ph~3, Cy~2Bu^n,CyBu~2^n; R^1=H, C~6H~5, p-CH~3C~6H~4, p-ClC~6H~4)。通过对产物的IR、1^HNMR、MS和元素的分析测定, 确定了它们的组成和结构。三丁基锡羧酸酯具有五配位的结构。生物活性测定结果表明, 这些化合物具有较好的杀螨和除草活性, 同时对植物病原菌也有一定的防治效果。     

Diketo compounds with (trifluoromethyl)trimethylsilane: double nucleophilic trifluoromethylation reactions

Reactions of various diketo compounds with (trifluoromethyl)trimethylsilane (Me3SiCF3) in the presence of catalytic amounts of cesium fluoride have been studied. gamma-Ketoesters, CH3COCH2CH2CO2R (R = Et, Bu), were reacted with 2 equiv of Me3SiCF3 at room temperature to give CH3C(OH)(CF3)CH2CH2COCF3 in good yield after hydrolysis. alpha-Diketones, R1COCOR2 (R1 = R2 = Ph; R1 = Ph, R2 = Me; R1 = R2 = Me; R1 = Me, R2 = Et), when reacted with Me3SiCF3, formed 1:1 or 1:2 addition products depending on the reaction conditions and stoichiometry used. Reactions of diones CH3COXCOCH3 (X = -CH2CH2-, -C6H4C6H4-, -CH2-) with Me3SiCF3 also led to the formation of the mono- or diaddition products depending on reaction conditions. With various kinds of substituted arylglyoxals, 2 equiv of Me3SiCF3 produced monoaddition products in 70-75% yield and diaddition products in 5-10% yield. One of the monoalcohols and two of the diols have been characterized by single-crystal X-ray analysis, and the presence of inter- and intramolecular hydrogen bonding has been confirmed.     

Catalytic carbonylation of functionalized diamines: application to the core structure of DMP 323 and DMP 450

W(CO)(6)-catalyzed carbonylation provides an alternative to phosgene or phosgene derivatives such as 1,1-carbonyldiimidazole (CDI) for the conversion of amines to ureas. As an illustration, the core structure of the HIV protease inhibitors DMP 323 and DMP 450 has been prepared by catalytic carbonylation of diamine intermediates from the original syntheses.     

The synthesis, characterisation and reactivity of 2-phosphanylethylcyclopentadienyl complexes of cobalt, rhodium and iridium

2-Phosphanylethylcyclopentadienyl lithium compounds, Li[C(5)R'(4)(CH(2))(2)PR(2)] (R = Et, R' = H or Me, R = Ph, R' = Me), have been prepared from the reaction of spirohydrocarbons C(5)R'(4)(C(2)H(4)) with LiPR(2). C(5)Et(4)HSiMe(2)CH(2)PMe(2), was prepared from reaction of Li[C(5)Et(4)] with Me(2)SiCl(2) followed by Me(2)PCH(2)Li. The lithium salts were reacted with [RhCl(CO)(2)](2), [IrCl(CO)(3)] or [Co(2)(CO)(8)] to give [M(C(5)R'(4)(CH(2))(2)PR(2))(CO)] (M = Rh, R = Et, R' = H or Me, R = Ph, R' = Me; M = Ir or Co, R = Et, R' = Me), which have been fully characterised, in many cases crystallographically as monomers with coordination of the phosphorus atom and the cyclopentadienyl ring. The values of nu(CO) for these complexes are usually lower than those for the analogous complexes without the bridge between the cyclopentadienyl ring and the phosphine, the exception being [Rh(Cp'(CH(2))(2)PEt(2))(CO)] (Cp' = C(5)Me(4)), the most electron rich of the complexes. [Rh(C(5)Et(4)SiMe(2)CH(2)PMe(2))(CO)] may be a dimer. [Co(2)(CO)(8)] reacts with C(5)H(5)(CH(2))(2)PEt(2) or C(5)Et(4)HSiMe(2)CH(2)PMe(2) (L) to give binuclear complexes of the form [Co(2)(CO)(6)L(2)] with almost linear PCoCoP skeletons. [Rh(Cp'(CH(2))(2)PEt(2))(CO)] and [Rh(Cp'(CH(2))(2)PPh(2))(CO)] are active for methanol carbonylation at 150 degrees C and 27 bar CO, with the rate using [Rh(Cp'(CH(2))(2)PPh(2))(CO)] (0.81 mol dm(-3) h(-1)) being higher than that for [RhI(2)(CO)(2)](-) (0.64 mol dm(-3) h(-1)). The most electron rich complex, [Rh(Cp'(CH(2))(2)PEt(2))(CO)] (0.38 mol dm(-3) h(-1)) gave a comparable rate to [Cp*Rh(PEt(3))(CO)] (0.30 mol dm(-3) h(-1)), which was unstable towards oxidation of the phosphine. [Rh(Cp'(CH(2))(2)PEt(2))I(2)], which is inactive for methanol carbonylation, was isolated after the methanol carbonylation reaction using [Rh(Cp'(CH(2))(2)PEt(2))(CO)]. Neither of [M(Cp'(CH(2))(2)PEt(2))(CO)] (M = Co or Ir) was active for methanol carbonylation under these conditions, nor under many other conditions investigated, except that [Ir(Cp'(CH(2))(2)PEt(2))(CO)] showed some activity at higher temperature (190 degrees C), probably as a result of degradation to [IrI(2)(CO)(2)](-). [M(Cp'(CH(2))(2)PEt(2))(CO)] react with MeI to give [M(Cp'(CH(2))(2)PEt(2))(C(O)Me)I] (M = Co or Rh) or [Ir(Cp'(CH(2))(2)PEt(2))Me(CO)]I. The rates of oxidative addition of MeI to [Rh(C(5)H(4)(CH(2))(2)PEt(2))(CO)] and [Rh(Cp'(CH(2))(2)PPh(2))(CO)] are 62 and 1770 times faster than to [Cp*Rh(CO)(2)]. Methyl migration is slower, however. High pressure NMR studies show that [Co(Cp'(CH(2))(2)PEt(2))(CO)] and [Cp*Rh(PEt(3))(CO)] are unstable towards phosphine oxidation and/or quaternisation under methanol carbonylation conditions, but that [Rh(Cp'(CH(2))(2)PEt(2))(CO)] does not exhibit phosphine degradation, eventually producing inactive [Rh(Cp'(CH(2))(2)PEt(2))I(2)] at least under conditions of poor gas mixing. The observation of [Rh(Cp'(CH(2))(2)PEt(2))(C(O)Me)I] under methanol carbonylation conditions suggests that the rhodium centre has become so electron rich that reductive elimination of ethanoyl iodide has become rate determining for methanol carbonylation. In addition to the high electron density at rhodium.     

Spectres de masse de P-anisyl-6 2H-Thiopyrannes Substitues ou non en 2 et Comportant en 3 un Groupement Fonctionnel

The six p-anisyl 2H-thiopyrans studied with substituents (R3) in position 3 (R3 = CHO, COCH3, CONH2 and CON?CH? N(CH3)2) gave [M - R3]⁺ (thiopyrylium cations) as the base peak. When R2 = OC2H5 R2 elimination gives other thiopyrylium cations. When R2 = OC2H5 and R3 = COCH3, C2H6 elimination leads to substituted 3-acetyl-2H-thiopyrannone. When R3 = CSNH2 or CSN = CH? N(CH3)2 the molecular ions form the base peaks. Loss of H2S or HCS? N(CH3)2 from R3 leads to a nitrile-containing ion.