- Ni-Catalyzed Enantioselective Conjunctive Coupling with C(sp3) Electrophiles: A Radical-Ionic Mechanistic Dichotomy
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The catalytic enantioselective conjunctive coupling of C(sp3) electrophiles can be accomplished with Ni catalysis. The enantioselectivity of the reaction is dependent on reaction mechanism with many substrates able to engage in an asymmetric process with Pybox-Ni complexes, whereas other substrates provide racemic product mixtures. The link between substrate structure and selectivity is addressed.
- Lovinger, Gabriel J.,Morken, James P.
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Read Online
- Catalyst-Free Reductive Coupling of Aromatic and Aliphatic Nitro Compounds with Organohalides
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A rare reductive coupling of nitro compounds with organohalides has been realized. The reaction is initiated by a partial reduction of the nitro group to a nitrenoid intermediate. Therefore, not only aromatic but also aliphatic nitro compounds are efficiently transformed into monoalkylated amines, with organohalides as the alkylating agent. Given the innate reactivity of the nitrenoid, a catalyst is not required, resulting in a high tolerance for aryl halide substituents in both starting materials.
- Rauser, Marian,Eckert, Raphael,Gerbershagen, Max,Niggemann, Meike
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supporting information
p. 6713 - 6717
(2019/04/14)
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- Phosphorothioic acids and related compounds as surrogates for H 2S-synthesis of chiral tetrahydrothiophenes
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The convenient preparation of chiral tetrahydrothiophenes (THTs) in high enantiopurity via phosphorothioic acids and related compounds is reported. We consider these to be safer alternatives to the use of H2S which is a highly toxic gas. Each o
- Robertson, Forest J.,Wu, Jimmy
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supporting information; experimental part
p. 2775 - 2780
(2012/03/22)
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- WATER-SOLUBLE CANNABINOIDS
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Water-soluble cannabinoid compounds that are agonists of CB1 and CB2 cannabinoid receptors are provided. The compounds are made water-soluble by derivatization of the alkyl side chain and/or the phenolic hydroxyl group of tetrahydroc
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Page/Page column 17; 2/21
(2008/06/13)
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- Benzimidazole derivatives
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Compounds, pharmaceutical compositions and methods are provided that are useful in the treatment of inflammatory and immune-related conditions or disorders. In particular, the invention provides compounds which modulate the expression and/or function of proteins involved in inflammation, immune response regulation and cell proliferation. The subject compounds are 2-amino-imidazole derivatives.
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- 5-thia-ω-substituted phenyl-prostaglandin E derivatives, process for producing the same and drugs containing the same as the active ingredient
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The present invention relates to 5-thia-ω-substituted phenylprostaglandin E derivatives of the formula (I) (wherein, all the symbols are as defined in the specification), process for producing them and pharmaceutical compositions comprising them as active
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- Fumarate salt of 4-(diethyl-3-(1-methyloctyl)-7,8,9,10-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol, 4-(diethyl-amino) butyric
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The present invention provides the fumarate salt of 4-(diethyl-3-(1-methyloctyl)-7,8,9,10-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-ol, 4-diethyl-amino)butyric acid ester, i.e. the compound having the following structure (I): STR1 and methods of t
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- Stereocontrolled construction of 1, 7-dimethyl A.B.C.[6.6.6] tricycles. Part I. transannular Diels-Alder reactions of 14-membered macrocycles containing frans-dienophiles
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Transannular Diels-Alder reactions of 14-membered macrocyclic trienes possessing a methyl substituent on both the diene and dienophile moiety have been investigated. Macrocyclic structures la, lb, and lc having cis-trans-trans (CTT), trans-cis-trans (TCT), and trans-trans-trans (TTT) geometries could be stereoselectively constructed by coupling appropriately functionalized dienes 5 and dienophile 4 following an intramolecular displacement of an allylic halide by the anion of an appropriately located dimethyl malonate unit. The transannular Diels-Alder reaction performed on la led to a mixture of four major tricyclic products, including 34 possessing the unexpected trans-anti-cis (TAC) stereochemistry. When heated at 300°C, macrocycle lb underwent an unique conversion via an ene-retroene, Diels-Alder process, producing the unexpected tricycle 41 (racemic form) containing five contiguous chiral centers. A rationale for the above experimental facts is presented. In contrast to the previous results, the transannular Diels-Alder reaction of macrocycle lc was straightforward, producing a 95% isolated yield of trans-anti-cis (TAC) tricycle 34. This investigation demonstrates a general methodology for the stereocontrolled synthesis of 1, 2-dimethyl A.B.C[6.6.6] tricyclic compounds, which are potential precursors to polycyclic natural products such as steroids and terpenes.
- Xu, Yao-Chang,Roughton, Andrew L.,Plante, Raymond,Goldstein, Solo,Deslongchamps, Pierre
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p. 1152 - 1168
(2007/10/02)
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- Transannular Diels-Alder reactions on 14-membered macrocyclic trienes. Part I: stereoselective syntheses of the macrocyclic trienes precursors
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Transannular Diels-Alder reactions on 14-membered macrocycles containing properly located diene and methyl-substituted dienophile units lead to A.B.C. tricycles related to steroids.To study the influence of the olefin and diene geometry on the stereochemical outcome of the Diels-Alder reaction it was necessary to prepare macrocyclic trienes of well-defined stereochemistry.Eight different types of macrocyclic trienes might be obtained by the coupling of appropriate dienophiles and dienes, namely, TTC, TTT, TCC, TCT, CTC, CTT, CCC, and CCT.In this paper (first in a series of two), the synthesis of appropriately functionalized dienophile and diene synthons, as well as their coupling reaction affording macrocyclic triene precursors, is described.
- Ndibwami, Alexis,Lamothe, Serge,Guay, Daniel,Plante, Raymond,Soucy, Pierre,et al.
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p. 695 - 713
(2007/10/02)
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- AN EFFICIENT CLEAVAGE OF LACTONES WITH BORON TRIIODIDE-N,N-DIETHYLANILINE COMPLEX
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Boron triiodide-N,N-diethylaniline complex efficiently cleaves lactones to the corresponding ω-iodocarboxylic acids and esters which are isolated in good yields.
- Narayana, C.,Reddy, N. K.,Kabalka, G. W.
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p. 6854 - 6856
(2007/10/02)
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- SN2 iodide displacement on unsymmetrical cyclic dioxenium salts. A stereoelectronically controlled reaction
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Iodide ion reacts with the cyclic dioxenium salts 1-6 to yield mixtures of iodoester and lactone plus alkyl iodide (Table 1).The formation of iodoester competing with the formation of lactone appears to be an unexpected result.It can, however, be explained by a stereoelectronic effect, similar to the anomeric effect in acetals, which is also responsible for the greater stability of the Z over the E form in dioxenium salts and in esters.
- Beaulieu, Normand,Deslongchamps, Pierre
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p. 164 - 167
(2007/10/02)
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- Phosphorus Tri-iodide (PI3), a Powerful Deoxygenating Agent
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On reaction with PI3 sulphoxides, selenoxides, aldehyde oximes, and primary nitroalkanes are transformed to sulphides, selenides, and nitriles, respectively.
- Denis, Jean Noel,Krief, Alain
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p. 544 - 545
(2007/10/02)
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