Conversion of Nitroalkenes into β-(Trichloromethyl) Nitroalkanes

The cesium fluoride-catalyzed reaction of (trichloromethyl) - trimethylsilane with conjugated nitroalkenes affords β-(trichloromethyl)nitroalkanes.     

Reactions of trichloromethyl radicals with organosilicon compounds

The photolysis of carbon tetrachloride in the presence of a number of organosilicon compounds has been investigated in the gas phase. The products obtained from the photolysis experiments were those expected from a chain reaction in which trichloromethyl radicals abstract hydrogen atoms from the organosilane. Arrhenius parameters for hydrogen atom transfer were determined relative to those for trichloromethyl radical combination. The activation energies for the reaction of methyl, trifluoromethyl, and trichloromethyl radicals with organosilicon compounds are compared and the results rationalized in terms of polar effects.     

Synthesis and properties of sym-triazine derivatives. 8. Synthesis of amino and alkoxy derivatives of sym-triazine containing fragments of a sterically-hindered phenol from 2,4-bis(trichloromethyl)-sym-triazines

The reactions of 2,4-bis(trichloromethyl)-6-substituted sym-triazines with several amino and hydroxy derivatives of 2,6-di-tert-butylphenol were studied. It is shown that, depending on the reaction conditions, one or both trichloromethyl groupings in the starting sym-triazines are replaced.See [1] for Communication 7.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 681–686, May, 1988.     

Insertion de germylenes dans la liaison etain—carbone. Germylenes a substituants perhalogenes

The electrophilic germylenes GeCl₂ and EtGeCl react with allyl- and (trichloromethyl)-trialkylstannanes with insertion in the SnC bond. The germylstannanes obtained give an α-elimination reaction leading to R₃SnCl and divalent species of germanium with an allyl or trichloromethyl substituent. The alkyl(dichloromethyl)germylenes are also obtained by an α-elimination reaction from the alkyl(dichloromethyl)methoxyhydrogermanes.     

Unexpected synthesis of 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane

The reaction of 2-amino-2-(trichloromethyl)tetrahydro-4-pyrone-5-spirocyclohexane with ethylenediamine afforded 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane, whereas 2-amino-5,5-dimethyl-2-(trichloromethyl)tetrahydro-4-pyrone gave 2-(3-hydroxy-2,2-dimethylpropionylmethylene)imidazolidine in low yield.     

Haloacetylated enol ethers. 11. Synthesis of 1-methyl- and 1-phenyl pyrazole-3(5)-ethyl esters. A one-pot procedure

A one-pot synthesis of 1-methyl- and 1-phenylpyrazole-3(5)-ethyl esters 2,3a-e by the cyclocondensation of β-alkoxyvinyl trichloromethyl ketones 1a-e with methyl and phenyl hydrazine hydrochloride under mild conditions, is reported. A study using compounds 1a-e with different substituents proved that these are versatile building blocks for the synthesis of pyrazole derivatives, having a 3(5)-ethoxycarbonyl substituent in good yields (60–89%). The hydrazine and β-alkoxyvinyl trichloromethyl ketone substituent effects on the reaction regiochemistry on the formation of the 1,3- and 1,5-isomer were observed.     

One-pot in situ formation and reaction of trimethyl(trichloromethyl)silane: application to the synthesis of 2,2,2-trichloromethylcarbinols

2,2,2-Trichloromethylcarbinols are 1 are valuable synthetic intermediates with a multitude of uses. A scalable procedure for the synthesis of TMS-protected-2,2,2-trichloromethylcarbinols and 2,2,2-trichloromethylcarbinols 1 was developed that employs the in situ generation and reaction of trimethyl(trichloromethyl)silane (CCl(3)-TMS). The procedure avoids the exposure of the carbonyl compounds to the strongly basic conditions typically used for this transformation and also avoids isolation of the difficult-to-handle CCl(3)-TMS. This procedure was applied to diastereoselective trichloromethyl additions to 2-substituted 4-piperidinones and to reactions with a variety of structurally diverse aldehydes and ketones.     

一锅法合成二硫醚的简便制备过程研究

双（三氯甲基）碳酸酯与三苯基膦反应生成的二氯三苯基膦在三乙胺存在下与 硫酚（醇）反应，合成了一系列收率良好的二硫醚化合物。该过程采用“一锅法” ，操作方便，后处理简单，条件温和，提供了一条合成二硫醚的重要路线。     

Total synthesis of 10-deoxymethynolide and narbonolide

A flexible and convenient approach was developed for the synthesis of 10-deoxymethynolide (1) and narbonolide (2), which are aglycones of the methymycin and the pikromycin families of macrolide antibiotics. These lactones are produced by pikromycin polyketide synthase from Streptomyces venezuelae. Polyketide lactones, 10-deoxymethynolide and narbonolide, which contain 12- and 14-membered rings, respectively, were synthesized efficiently. These target lactones were retrosynthetically divided into three parts and assembled by using an asymmetric aldol reaction, the Yamaguchi esterification, and ring-closing metathesis. The ring-closing metathesis reaction catalyzed by the second-generation Grubbs catalyst is particularly efficient in preparing these macrocyclic polyketide lactones.     

Trichloromethyl Anion Chemistry from Trimethylsilyl Trichloroacetate

The reaction of trimethylsilyl trichloroacetate with aldehydes and Retones in the presence of fluoride ion gives the trichloromethyl adducts. With potassium fluoride the reaction with cyclohexenone and crotonaldehyde results in clear 1,2 addition.     

Switching from S- to R-selectivity in the Candida antarctica lipase B-catalyzed ring-opening of omega-methylated lactones: tuning polymerizations by ring size

Novozym 435-catalyzed ring-opening of a range of omega-methylated lactones demonstrates fascinating differences in rate of reaction and enantioselectivity. A switch from S- to R-selectivity was observed upon going from small (ring sizes or=8). This was attributed to the transition from a cisoid to a transoid conformational preference of the ester bond on going from small to large lactones. The S-selectivity of the ring-opening of the small, cisoid lactones was low to moderate, while the R-selectivity of the ring-opening of the large transoid lactones was surprisingly high. The S-selectivity of the ring-opening of the small, cisoid lactones combined with the established R-selectivity of the transesterification of (aliphatic) secondary alcohols prevented polymerization from taking place. Ring-opening of the large, transoid lactones was R-selective with high enantioselectivity. As a result, these lactones could be polymerized, without exception, by straightforward kinetic resolution polymerization, yielding the enantiopure R-polyester with excellent enantiomeric excess (>99%).     

A novel chain reaction induced by cathodic reduction. Addition of trichloromethyl anion to aldehydes or vimyl acetate

A novel chain reaction induced by cathodic reduction was found in the reaction system consisting of carbon tetrachloride, chloroform, and electrophiles such as aldehydes or vinyl acetate. The current efficiency of addition of trichloromethyl anion to electrophiles was extremely high. Synthesis of an analogue of ethyl chrysanthemate using this new reaction was also described.     

Lactones. Part 16: Lactonization of γ,δ-epoxy esters with p-toluenesulfonic acid monohydrate

The reaction of cyclic γ,δ-epoxy esters with p-toluenesulfonic acid monohydrate is described. The reaction carried out in benzene or methylene chloride gave tosyloxy lactones as product. The ethoxy or methoxy lactones were obtained when ethanol or methanol were used as solvent. A mechanism of this lactonization is proposed.     

Experimental and Theoretical Mechanistic Study on the Thermal Decomposition of 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline

The present paper is a continuation of comprehensive study regarding to synthesis and properties of pyrazoles and their derivatives. In its framework an experimental and theoretical studies of thermal decomposition of the 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline were performed. It was found, that the decompositions of the mentioned pyrazoline system in the solution and at the melted state proceed via completely different molecular mechanisms. These mechanisms have been explained in the framework of the Molecular Electron Density Theory (MEDT) with the computational level of B3LYP/6-31G(d). A Bonding Evolution Theory (BET) examination of dehydrochlorination of the 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline permits elucidation of the molecular mechanism. It was found, that on the contrary for most known HCl extrusion processes in solution, this reaction is realised via single-step mechanism.     

Fused-s-triazino heterocycles. XI. Displacement reactions of 7,9-dichloro-2,5-bis(trichloromethyl)-1,3,4,6,9b-pentaazaphenalene

The preparation of 7,9-dichloro-2,5-bis(trichloromethyl)-1,3,4,6,9b-pentaazaphenalene ( 1e ) by the chlorination of 2-trichloromethyl-5-methyl-1,3,4,6,9b-pentaazaphenalene ( 1a ) using molecular chlorine is described. Displacement of one or both trichloromethyl groups of 1e by a variety of nucleophiles led to the corresponding 7,9-dichloro-2,5-bis-substituted or 7,9-dichloro mixed 2,5-disubstituted derivatives. The reaction of 1a with N-chlorosuccinimide proved not to be a useful route to 1e but instead led primarily to substitution of positions 7 and/or 9 by chlorine.     

60]Fullerene-fused lactones: manganese(III) acetate-mediated synthesis and novel reductive ring opening

[reaction: see text] [60]Fullerene-fused lactones were prepared by the manganese(III) acetate-mediated reactions of [60]fullerene with carboxylic acids, carboxylic anhydrides, or malonic acids. Novel reductive ring opening of the lactones with Grignard reagents was observed.     

Etude de l'action des alkylmagnesiens primaires et arylmagnesiens sur les anhydrides tricycliques pontes

The reaction of primary alkyl and aromatic Grignard reagents with bridged tricyclic di-carboxylic anhydrides gives the corresponding dialkylated tricyclic lactones via di-addition process. The lactones were transformed by retro-Diels-Alder reactions into 4,4-dialkylated butenolides.     

Catalytic atropo-enantioselective reduction of biaryl lactones to axially chiral biaryl compounds

The atropo-enantioselective borohydride reduction with dynamic kinetic resolution of biaryl lactones was catalyzed by an optically active beta-ketoiminatocobalt(II) complex to afford optically active biaryl compounds. Chiral HPLC analysis of the starting biaryl lactones was performed at various temperatures to determine suitable reaction conditions for dynamic kinetic resolution. Various types of axially chiral biaryl compounds were obtained with high enantioselectivity.     

Synthesis and properties of derivatives ofsym-triazine. 16. Synthesis of amine and diamine derivatives ofsym-triazine containing sterically hindered phenol groups from 6-alkyl(aryl)thio-2,4-bis(trichloromethyl)-sym-triazine

The reaction of 6-alkyl(aryl)thio-2,4-bis(trichloromethyl)-sym-triazines with ammonia and primary and secondary amines is studies. It is shown that, depending on the reaction conditions, the replacement of either one or both of the trichloromethyl groups takes place. 6-alkyl(aryl)thio-2,4-diamono-sym-triazines containing sterically hindered phenol groups are synthesized.I. M. Gubkin State Petroleum and Gas Academy, Moscow, 117917. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 224–231., Ferbruary, 1995. Original article submitted December 21, 1994.     

Fluorinated β-lactones and poly(β-hydroxyalkanoate)s: synthesis via epoxide carbonylation and ring-opening polymerization

Efficient and mild reaction conditions were developed for the catalytic carbonylation of fluorinated epoxides to their corresponding β-lactones. Six new lactones with fluorinated side chains were prepared in high isolated yields. These lactones were polymerized to form a series of new poly(β-hydroxyalkanoate)s with fluorinated side chains, and their properties were examined with respect to their hydrocarbon analogs. Finally, copolymerizations were performed with fluorinated lactones and β-butyrolactone, which resulted in tapered copolymers rather than the expected random copolymers.