- A Copper-Catalyzed Aerobic [1,3]-Nitrogen Shift through Nitrogen-Radical 4-exo-trig Cyclization
-
A novel radical [1,3]-nitrogen shift catalyzed by copper diacetate under an oxygen atmosphere (1 atm) has been developed for the construction of a diverse range of indole derivatives from α,α-disubstituted benzylamine. In this reaction, oxygen was used as a clean terminal oxidant, and water was produced as the only by-product. Five inert bonds were cleaved, and two C?N bonds and one C?C double bond were constructed in one pot during this transformation. This unique method demonstrated broad application protential for the late-stage modification of biologically active natural products and drugs. Mechanistic investigations indicate that a unique 4-exo-trig cyclization of an aminyl radical onto a phenyl ring is involved in the catalytic cycle.
- Li, Yan,Wang, Rui,Wang, Tao,Cheng, Xiu-Fen,Zhou, Xin,Fei, Fan,Wang, Xi-Sheng
-
supporting information
p. 15436 - 15440
(2017/11/01)
-
- C-S bond cleavage in aromatic sulfide radical cations
-
The results of our recent studies of the structural effects on the C-S bond fragmentation process of aromatic sulfur radical cations are reported.
- Lanzalunga, Osvaldo
-
p. 322 - 330
(2013/07/25)
-
- Dynamic path bifurcation in the Beckmann reaction: Support from kinetic analyses
-
The reactions of oximes to amides, known as the Beckmann rearrangement, may undergo fragmentation to form carbocations + nitriles when the migrating groups have reasonable stability as cations. The reactions of oxime sulfonates of 1-substituted-phenyl-2-propanone derivatives (7-X) and related substrates (8-X, 9a-X) in aqueous CH3CN gave both rearrangement products (amides) and fragmentation products (alcohols), the ratio of which depends on the system; the reactions of 7-X gave amides predominantly, whereas 9a-X yielded alcohols as the major product. The logk-logk plots between the systems gave excellent linear correlations with slopes of near unity. The results support the occurrence of path bifurcation after the rate-determining TS of the Beckmann rearrangement/fragmentation reaction, which has previously been proposed on the basis of molecular dynamics simulations. It was concluded that path-bifurcation phenomenon could be more common than thought and that a reactivity-selectivity argument based on the traditional TS theory may not always be applicable even to a well-known textbook organic reaction.
- Yamamoto, Yutaro,Hasegawa, Hiroto,Yamataka, Hiroshi
-
experimental part
p. 4652 - 4660
(2011/07/29)
-
- NOVEL BENZAMIDE DERIVATIVES AS MODULATORS OF THE FOLLICLE STIMULATING HORMONE
-
The present invention provides new compounds of formula I, wherein Q, R1, R2, R4, R5, R6, Xi, R7, R8, M and G1 nare defined as in formula I; invention compounds are modulators of follicle-stimulating hormone - ("FSH") which are useful for male and female contraception as well as other disorders modulated by FSH receptor.
- -
-
Page/Page column 114
(2008/12/04)
-
- Catalytic oxidation of C-H bonds
-
The invention provides a catalytic, chemospecific and stereospecific method of oxidizing a wide variety of substrates without unwanted side reactions. Essentially, the method of the instant invention, under relatively mild reaction conditions, catalytically, stereospecifically and chemospecifically inserts oxygen into a hydrocarbon C—H bond. Oxidation (oxygen insertion) at a tertiary C—H bond to form an alcohol (and in some cases a hemiacetal) at the tertiary carbon is favored. The stereochemistry of an oxidized tertiary carbon is preserved. Ketones are formed by oxidizing a secondary C—H bond and ring-cleaved diones are formed by oxidizing cis tertiary CH bonds.
- -
-
-
- Studies on development of sufficiently chemoselective N-acylation reagents: N-Acyl-N-(2,3,4,5,6-pentafluorophenyl)methanesulfonamides
-
A variety of storable N-acyl-N-(2,3,4,5,6-pentafluorophenyl)methanesulfonamides (4a-e) prepared from N-2,3,4,5,6-pentafluorophenylmethanesulfonamide (3), have been developed after systematic research on the structure-reactivity relationship and were found to serve as N-acylation reagents exhibiting sufficiently good chemoselectivity. (C) 2000 Elsevier Science Ltd.
- Kondo, Kazuhiro,Sekimoto, Erika,Nakao, Junko,Murakami, Yasuoki
-
p. 5843 - 5856
(2007/10/03)
-
- Photoinduced electron transfer reactions of benzyl phenyl sulfides promoted by 9,10-dicyanoanthracene
-
The photoinduced oxidation of benzyl phenyl sulfides 1-3 has been investigated in MeCN using 9,10-dicyanoanthracene as sensitizer in the presence of O2. In this reaction a sulfide radical cation is formed, which undergoes one or more of the three main reaction pathways opened to these species: C-S bond cleavage, C-H bond cleavage and S-oxidation. The former route (leading to benzylic products) was observed with all the substrates investigated, whereas the second (leading to benzaldehydes) operates only with 1 and 2. Formation of sulfoxides was found solely in the photooxidation of 1. The influence of substrate structures on the relative contribution of the three pathways as well as the role of O2- in this respect are discussed.
- Baciocchi, Enrico,Crescenzi, Cristina,Lanzalunga, Osvaldo
-
p. 4469 - 4478
(2007/10/03)
-
- The ortho-substituted N,N-diacetylaniline as a selective acetylating reagent
-
Selective acetylation of the less hindered amino group in the presence of the more hindered amino group with the use of 2-trifluoromethyl-N,N-diacetylaniline 2c is described. This acetylation with 2c yielded the corresponding less hindered monoacetamide exclusively, simply, conveniently, and in good yields.
- Murakami, Yasuoki,Kondo, Kazuhiro,Miki, Kazuki,Akiyama, Yoko,Watanabe, Toshiko,Yokoyama, Yuusaku
-
p. 3751 - 3754
(2007/10/03)
-
- 4-amino(alkyl)cyclohexane-1-carboxamide compound and use thereof
-
4-Amino(alkyl)cyclohexane-1-carboxamide compounds of the formula (I) STR1 wherein each symbol is as defined in the Specification, isomers thereof and pharmaceutically acceptable acid addition salts thereof. The 4-amino(alkyl)cyclohexane-1-carboxamide comp
- -
-
-
- Amidomercuriation: A General Addition of Amides and Related Compounds to Olefins
-
The addition of different carboxamides and related compounds such as urethane or urea to olefins using mercury(II) nitrate followed by sodium borohydride reduction to give the corresponding N-substituted amides, urethanes, or ureas, respectively, is described.The monoalkylated ureas, through the same amidomercuriation-demercuriation procedure, yield symmetrical and unsymmetrical N,N'-disubstituted ureas.This amidomercuriation-demercuriation process provides a new, convenient, and general method for the Markovnikov amidation of carbon-carbon double bonds.
- Barluenga, Jose,Jimenez, Carmen,Najera, Carmen,Yus, Miguel
-
p. 591 - 593
(2007/10/02)
-
- Reactions of Cerium(IV) Ammonium Nitrate with Aromatic Compounds in Acetonitrile. Part 1. The Mechanism of Side-chain Substitution
-
Benzene, alkylbenzenes, and phenolic ethers react with cerium(IV) ammonium nitrate in acetonitrile to give nitrocompounds and (if α-hydrogen atoms are present) also the products of side-chain substitution.With many substrates, the major products of side-chain substitution are benzyl nitrates but compounds which can give rise to particularly stable benzyl cations give mainly products from reaction with the solvent.Relative rates of side-chain substitution have been determined by the competition method: the results indicate reaction via a radical cation and the isotope effect kH/kD=2.3 observed in reactions with 10>-p-xylene suggests that proton loss from this radical cation is, at least partly, rate-determining.
- Dinctuerk, Suphi,Ridd, John H.
-
p. 961 - 964
(2007/10/02)
-
- Amidomercuration; a New and Regiospecific Addition of Amides to Olefins
-
The reaction of olefins with anhydrous mercury(II) nitrate in the presence of primary amides leads, after in situ alkaline sodium borohydride reduction, to the corresponding N-substituted amides; this procedure provides a new, convenient method for the Markovnikov amidation of carbon-carbon double bonds.
- Barluenga, Jose,Jimenez, Carmen,Najera, Carmen,Yus, Miguel
-
p. 670 - 671
(2007/10/02)
-