- Visible-Light-Induced Vicinal Dichlorination of Alkenes through LMCT Excitation of CuCl2
-
This work demonstrates photoredox vicinal dichlorination of alkenes, based on the homolysis of CuCl2 in response to irradiation with visible light. This catalysis proceeds via a ligand to metal charge transfer process and provides an exciting opportunity for the synthesis of 1,2-dichloride compounds using an inexpensive, low-molecular-weight chlorine source. This new process exhibits a wide substrate scope, excellent functional group tolerance, extraordinarily mild conditions and does not require external ligands. Mechanistic studies show that the ready formation of chlorine atom radicals is responsible for the facile formation of C?Cl bonds in this synthetic process.
- Li, Jingjing,Lian, Pengcheng,Long, Wenhao,Wan, Xiaobing,Zheng, Yonggao
-
supporting information
p. 23603 - 23608
(2020/10/29)
-
- NMP-mediated chlorination of aliphatic alcohols with aryl sulfonyl chloride for the synthesis of alkyl chlorides
-
NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C–Cl bond in good to excellent yields with mild conditions and broad substrate scope.
- Zheng, Dagui,Mao, Liu-Liang,Zhu, Xian-Hong,Zhou, An-Xi
-
supporting information
p. 2793 - 2800
(2018/11/06)
-
- Halogenation through Deoxygenation of Alcohols and Aldehydes
-
An efficient reagent system, Ph3P/XCH2CH2X (X = Cl, Br, or I), was very effective for the deoxygenative halogenation (including fluorination) of alcohols (including tertiary alcohols) and aldehydes. The easily available 1,2-dihaloethanes were used as key reagents and halogen sources. The use of (EtO)3P instead of Ph3P could also realize deoxy-halogenation, allowing for a convenient purification process, as the byproduct (EtO)3Pa?O could be removed by aqueous washing. The mild reaction conditions, wide substrate scope, and wide availability of 1,2-dihaloethanes make this protocol attractive for the synthesis of halogenated compounds.
- Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
-
supporting information
p. 3061 - 3064
(2018/05/28)
-
- Mild Aliphatic and Benzylic Hydrocarbon C-H Bond Chlorination Using Trichloroisocyanuric Acid
-
We present the controlled monochlorination of aliphatic and benzylic hydrocarbons with only 1 equiv of substrate at 25-30 °C using N-hydroxyphthalimide (NHPI) as radical initiator and commercially available trichloroisocyanuric acid (TCCA) as the chlorine source. Catalytic amounts of CBr4 reduced the reaction times considerably due to the formation of chain-carrying ·CBr3 radicals. Benzylic C-H chlorination affords moderate to good yields for arenes carrying electron-withdrawing (50-85%) or weakly electron-donating groups (31-73%); cyclic aliphatic substrates provide low yields (24-38%). The products could be synthesized on a gram scale followed by simple purification via distillation. We report the first direct side-chain chlorination of 3-methylbenzoate affording methyl 3-(chloromethyl)benzoate, which is an important building block for the synthesis of vasodilator taprostene.
- Combe, Sascha H.,Hosseini, Abolfazl,Parra, Alejandro,Schreiner, Peter R.
-
p. 2407 - 2413
(2017/03/11)
-
- Direct halogenation of alcohols with halosilanes under catalyst- and organic solvent-free reaction conditions
-
A chemoselective method for the direct halogenation of different types of alcohols with halosilanes under catalyst- and solvent-free reaction conditions (SFRC) is reported. Various primary, secondary and tertiary benzyl alcohols and tertiary alkyl alcohols were directly transformed to the corresponding benzyl and alkyl halides, respectively, using chlorotrimethylsilane (TMSCl) and bromotrimethylsilane (TMSBr).
- Ajvazi, Njomza,Stavber, Stojan
-
supporting information
p. 2430 - 2433
(2016/05/19)
-
- Microwave assisted solid additive effects in simple dry chlorination reactions with n-chlorosuccinimide
-
Solid additives participate in the dry microwave assisted chlorination reaction of N-chlorosuccinimide with the xylenes affecting both yields and chemoselectivities. Total yields can be increased up to nine times for simple alkylaromatics and chemoselectivities can be altered according to the desired ring or α-side chlorination product by choosing the appropriate additive. We believe that in these reactions the solid additives play a very important role by increasing yields and affecting chemoselectivities, as well as behaving as microwave energy absorbers that consequently aid the transfer of heat to the active reagents.
- Bucos, Madalina,Villalonga-Barber, Carolina,Micha-Screttas, Maria,Steele, Barry R.,Screttas, Constantinos G.,Heropoulos, Georgios A.
-
experimental part
p. 2061 - 2065
(2010/04/26)
-
- Design, synthesis, and antitumor activity of new bis-aminomethylnaphthalenes
-
A new series of bis-aminomethylnaphthalenes were synthesized in satisfactory overall yield, through a simple synthetic strategy using reductive amination. The DNA binding properties of these compounds have been examined and compared to those of reference drugs using an UV spectroscopy method. The compounds were evaluated for their in vitro anticancer activity and some of them were studied in vivo. Compound 15 exhibited remarkable antitumor activity and represents a novel template for anticancer chemotherapy and can serve as a new lead compound.
- Bollini, Mariela,Casal, Juan Jose,Bruno, Ana Maria
-
p. 8003 - 8010
(2008/12/23)
-
- Double elimination protocol for the synthesis of arylene ethynylenes containing heteroaromatic rings
-
The double elimination reaction of β-substituted sulfones offers a versatile strategy for synthesis of arylene ethynylene kits containing heteroaromatic rings. A sequence of aldol reaction between α-sulfonyl carbanion and aldehyde, trapping the resulting aldolate to give β-substituted sulfone, and double elimination of this intermediate can be integrated in one pot. This protocol allows thiophene, pyridine, and ferrocene units to be accommodated in phenylene ethynylene arrays.
- Orita, Akihiro,Ye, Fangguo,Babu, Govindarajulu,Ikemoto, Tomohiro,Otera, Junzo
-
p. 716 - 727
(2007/10/03)
-
- Arylmethyl radicals from arylmethoxybromodiazirines
-
(Chemical Equation Presented) Photolytic decompositions of 3-arylmethoxy-3-bromodiazirines afford arylmethyl radicals by homolyses of the diazirines' excited states.
- Moss, Robert A.,Fu, Xiaolin
-
p. 3353 - 3356
(2007/10/03)
-
- Design, synthesis, and structure-activity relationships of haloenol lactones: Site-directed and isozyme-selective glutathione S-transferase inhibitors
-
Overexpression of glutathione S-transferase (GST), particularly the GST-π isozyme, has been proposed to be one of the biochemical mechanisms responsible for drug resistance in cancer chemotherapy, and inhibition of overexpressed GST has been suggested as an approach to combat GST-induced drug resistance. 3-Cinnamyl-5(E)-bromomethylidenetetrahydro-2-furanone (1a), a lead compound of site-directed GST-π inactivator, has been shown to potentiate the cytotoxic effect of cisplatin on tumor cells. As an initial step to develop more potent and more selective haloenol lactone inactivators of GST-π, we examined the relationship between the chemical structures of haloenol lactone derivatives and their GST inhibitory activity. A total of 16 haloenol lactone derivatives were synthesized to probe the effects of (1) halogen electronegativity, (2) electron density of aromatic rings, (3) molecular size and rigidity, (4) lipophilicity, and (5) aromaticity on the potency of GST-π inactivation. The inhibitory potency of each compound was determined by time-dependent inhibition tests, and recombinant human GST-π was used to determine their inhibitory activity. Our structure-activity relationship studies demonstrated that (1) reactivity of the halide leaving group plays a weak role in GST inactivation by the haloenol lactones, (2) aromatic electron density may have some influence on the potency of GST inactivation, (3) high rigidity likely disfavors enzyme inhibition, (4) lipophilicity is inversely proportional to enzyme inactivation, and (5) an unsaturated system may be important for enzyme inhibition. This work facilitated understanding of the interaction of GST-π with haloenol lactone derivatives as site-directed and isozyme-selective inactivators, possibly potentiating cancer chemotherapy.
- Wu, Zhixing,Minhas, Gurpreet Singh,Wen, Dingyi,Jiang, Hualiang,Chen, Kaixian,Zimniak, Piotr,Zheng, Jiang
-
p. 3282 - 3294
(2007/10/03)
-
- C17,20-lyase inhibitors I. Structure-based de novo design and SAR study of C17,20-lyase inhibitors.
-
Novel nonsteroidal C(17,20)-lyase inhibitors were synthesized using de novo design based on its substrate, 17 alpha-hydroxypregnenolone, and several compounds exhibited potent C(17,20)-lyase inhibition. However, in vivo activities were found to be short-lasting, and in order to improve the duration of action, a series of benzothiophene derivatives were evaluated. As a result, compounds 9h, (S)-9i, and 9k with nanomolar enzyme inhibition (IC(50)=4-9 nM) and 9e (IC(50)=27 nM) were identified to have powerful in vivo efficacy with extended duration of action. The key structural determinants for the in vivo efficacy were demonstrated to be the 5-fluoro group on the benzothiophene ring and the 4-imidazolyl moiety. Superimposition of 9k and 17 alpha-hydroxypregnenolone demonstrated their structural similarity and enabled rationalization of the pharmacological results. In addition, selected compounds were also identified to be potent inhibitors of human enzyme with IC(50) values of 20-30 nM.
- Matsunaga, Nobuyuki,Kaku, Tomohiro,Itoh, Fumio,Tanaka, Toshimasa,Hara, Takahito,Miki, Hiroshi,Iwasaki, Masahiko,Aono, Tetsuya,Yamaoka, Masuo,Kusaka, Masami,Tasaka, Akihiro
-
p. 2251 - 2273
(2007/10/03)
-
- A one-pot method for the efficient conversion of aryl- and acyl-substituted methyl alcohols into chlorides
-
A one-pot and efficient conversion of aryl- and acyl-substituted methyl alcohols into the corresponding chlorides is described, which involved tosylation with tosyl chloride and triethylamine in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) in CH2Cl2, followed by methanol-facilitated replacement of the tosylates with chloride. This mild method is readily amenable to large-scale synthesis.
- Lai, Gaifa,Tan, Ping-Zhong,Ghoshal, Pallab
-
p. 1727 - 1732
(2007/10/03)
-
- Pyrimidin-4-one compounds
-
Compound of formula (I): wherein: R1, R2, R3 and R4, which may be the same or different, each represent a hydrogen atom, a halogen atom or a group selected from alkyl, alkoxy, polyhaloalkyl, hydroxy, cyano, nitro and amino, ?or R1 with R2, R2 with R3, or R3 with R4, together with the carbon atoms carrying them, form an optionally substituted benzene ring or an optionally substituted heteroaromatic ring, X represents an oxygen atom or a methylene group, A represents an alkylene chain, ?represents an optionally substituted, unsaturated, nitrogen-containing heterocycle and R5 represents an alkyl group, its enantiomers and diastereoisomers, and addition salts thereof with a pharmaceutically acceptable acid. a medicinal products containing the same are useful as a double α2/5-HT2c antagonist.
- -
-
-
- Direct conversion of carbonyl compounds into organic halides: Indium(III) hydroxide-catalyzed deoxygenative halogenation using chlorodimethylsilane
-
The reaction of carbonyls and chlorodimethylsilane was effectively catalyzed by indium(III) hydroxide and afforded the corresponding deoxygenative chlorination products, in which the carbonyl carbon accepted two nucleophiles (H and Cl) with releasing oxygen. Only In(OH)3 catalyzed the reaction, and typical Lewis acids such as TiCl4, AlCl3, and BF3·OEt2 showed no catalytic activity. The reaction mechanism of this deoxygenative chlorination includes initial hydrosilylation followed by chlorination. Other nucleophiles such as allyl or iodine were available for this methodology. The moderate Lewis acidity of indium catalyst enabled chemoselective reaction, and therefore ester, nitro, cyano, or halogen groups were not affected during the reaction course. Copyright
- Onishi, Yoshiyuki,Ogawa, Daigo,Yasuda, Makoto,Baba, Akio
-
p. 13690 - 13691
(2007/10/03)
-
- Lipophilic 4-isoxazolyl-1,4-dihydropyridines: Synthesis and structure- activity relationships
-
A series of 4-isoxazolyl-1,4-dihydropyridines bearing lipophilic side chains at the C-5 position of the isoxazole ring have been prepared. The calcium channel antagonistic activity of these compounds has been evaluated. A hypothetical model for binding of these compounds in the calcium channel is proposed, and the validity of this model is evaluated based on the SAR of this series of calcium binding, especially for the two most active derivatives, 1a,g. The solid-state structure for the most active compound, 1a, has also been determined, and its important features are reported.
- Natale, Nicholas R.,Rogers, Mark E.,Staples, Richard,Triggle, David J.,Rutledge, Aleta
-
p. 3087 - 3093
(2007/10/03)
-
- An Investigation on the Reactions of Naphthocyclopropene
-
In order to investigate the reactivity of naphthocyclopropene (2), the reactions with various dienophiles, dienes and electrophiles was examined.Reaction of 2 with tetracyanoethylene, 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione, 1,3-diphenylisobenzofuran and benzyne afforded the insertion products 3,4,6,10.Cheletropic addition of dichlorocarbene to 2 gave 1,1-dichloronaphthocyclobutene (11).Hydrolysis and reductive elimination of 12 provided naphthocyclobutenone (12) and naphthocyclobutene (13), respectively.Naphthocyclopropene reacted with the different electrophiles like acetic acid, HCl, maleic acid, iodine, bromine, ethanol, and hydrogen afforded the corresponding ring-opening products 14, 15, 16, 17, 18, 19, 20 and 21, respectively.
- Saracoglu, Nurullah,Durucasu, Inci,Balci, Metin
-
p. 10979 - 10986
(2007/10/02)
-
- Syntheses of unsymmetrically N,N′-bis (substituted)-4,13-diaza-18-crown-6-ether derivatives as a new electron donor-spacer-acceptor triad
-
A simple and general synthetic strategy potentially applicable for the preparation of a wide variety of unsymmetrically N,N′-bis(substituted)-4, 13-diaza-18-crown-6-ether derivatives was reported.
- Morimoto, Minoru,Fukui, Keijiro,Kawasaki, Norioki,Iyoda, Tomokazu,Shimidzu, Takeo
-
-
- Photosensitive compound
-
Photosensitive compounds having preferably a functional group such as --SO2 Cl, --SO3 H, --SO3 R, STR1 (R, R', R" being alkyl) on a terminal benzene or naphthalene ring connected via a methylene group and STR2 moiety are improved in sensitivity to light and thermal stability, and thus useful in a photo resist.
- -
-
-
- Halogenative Allylation and Reduction of Aromatic Acetals by Double Substitution of Alkoxyl Groups in Acetal
-
In the presence of excessive amount of acetyl halide along with a catalytic amount of tin(II) halide, aromatic acetals react with allyltrimethylsilane or triethylsilane to give α-allylbenzyl halides or benzyl halides, respectively, in good to excellent yields.
- Oriyama, Takeshi,Iwanami, Katsuyuki,Tsukamoto, Kazuhisa,Ichimura, Yuichi,Koga, Gen
-
p. 1410 - 1412
(2007/10/02)
-
- Analogues of clofibrate and clobuzarit containing fluorine in the side chains
-
A series of analogues of clofibrate and 2-[4-(4-chlorophenyl)phenylmethoxy]-2-methylpropionic acid (clobuzarit) has been prepared by replacing the methyl groups by trifluoromethyl groups and changing the aromatic moiety. The activity of these compounds has been assayed on the plasma levels of cholesterol, Total Esterified Fatty Acids (T.E.F.A.) and fibrinogen in rats. It appears that derivatives of the first series which contain only one trifluoromethyl group are hypocholesterolaemic and that many mono- of bis- trifluoromethyl derivatives of the second series lower the levels of both cholesterol and T.E.F.A. in contrast to clobuzarit.
- Haydock,Mulholland,Telford,et al.
-
p. 205 - 214
(2007/10/02)
-
- ARYLMETHYL ISOCYANATES
-
Chloromethyl isocyanate reacts readily with aromatic hydrocarbons in the presence of anhydrous ferric chloride or other catalysts of the Friedel-Crafts reaction with the formation of arylmethyl isocyanates.The latter add alcohols and amines readily, being converted into the corresponding substituted urethanes and ureas.When heated in the presence of catalytic amounts of 1,3-dimethylphosphol-3-ene they give substituted carbodiimides.
- Kozhushko, B. N.,Lomakina, A. V.,Paliichuk, Yu. A.,Shokol, V. A.
-
p. 654 - 660
(2007/10/02)
-
- Stereospecific Synthesis of Tetrahydrobenzisoquinoline Derivatives
-
A new synthesis of optically active tetrahydrobenzisoquinolines is described.Cyclization of N-arylalkylalanines with retention of configuration was achieved by mild intramolecular Friedel-Crafts acylation.The compounds synthesized this way represent simple analogues of phenanthroindolizidine alkaloids.Some features of the n.m.r. spectra of cyclized and open-chain intermediates are discussed.
- Gellert, Emery,Kumar, Naresh,Tober, Deirdre
-
p. 157 - 163
(2007/10/02)
-
- Process for tris(aralkyl)phosphines
-
In a solution that is free of bases and free of oxygen and which contains at least four molar proportions of the reactant tris(hydroxymethyl)phosphine for every three molar proportions of an aralkyl halide reactant, the following reaction produces tris(aralkyl)phosphine product: after separation of the phosphine product, the phosphonium salt by-products can be converted to tris(hydroxymethyl)phosphine by the addition of a base.
- -
-
-