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Journal of the American Chemical Society Apr 2014A carbodicarbene (CDC)-based pincer ligand scaffold is reported, along with its application to site-selective Rh(I)-catalyzed intermolecular hydroamination of 1,3-dienes...
A carbodicarbene (CDC)-based pincer ligand scaffold is reported, along with its application to site-selective Rh(I)-catalyzed intermolecular hydroamination of 1,3-dienes with aryl and alkyl amines. To the best of our knowledge, this is the first example of the use of a well-defined CDC complex as an efficient catalyst. Transformations proceed in the presence of 1.0-5.0 mol % Rh complex at 35-120 °C; allylic amines are obtained in up to 97% yield and with >98:2 site selectivity.
Topics: Allyl Compounds; Amination; Amines; Catalysis; Coordination Complexes; Methane; Models, Molecular; Phosphines; Polyenes; Rhodium
PubMed: 24742315
DOI: 10.1021/ja502275w -
Organic Letters Aug 2014A Pd/Ag bimetallic system has been developed for the decarboxylative allylation of ortho-nitrobenzoic esters in an intramolecular fashion. In contrast to the typical...
A Pd/Ag bimetallic system has been developed for the decarboxylative allylation of ortho-nitrobenzoic esters in an intramolecular fashion. In contrast to the typical sp(2)-sp(3) cross-coupling approach which requires air and moisture sensitive preformed organometallic reagents, we provide an alternative route to the synthesis of ortho-allyl nitroarenes from the corresponding ortho-nitrobenzoic acid derivatives. The reaction proceeds through a mechanistically distinct decarboxylative metalation pathway. A cooperative reactivity of palladium and silver is crucial for the reaction outcome.
Topics: Allyl Compounds; Catalysis; Esters; Molecular Structure; Nitrobenzoates; Palladium; Stereoisomerism
PubMed: 25055344
DOI: 10.1021/ol5017349 -
Archives of Environmental Health 1987Potential adverse health effects from occupational exposure to 1,3-dichloro-propene (DCP) are reviewed and hazards assessed. Further toxicologic evaluations should be... (Review)
Review
Potential adverse health effects from occupational exposure to 1,3-dichloro-propene (DCP) are reviewed and hazards assessed. Further toxicologic evaluations should be conducted using only high-purity material that is free from possibly confounding impurities and stabilizers. Safety considerations when handling the material are included.
Topics: Allyl Compounds; Animals; Carcinogens; Environmental Exposure; Humans; Hydrocarbons, Chlorinated; Insecticides; Mutagenicity Tests
PubMed: 3330654
DOI: 10.1080/00039896.1987.9935823 -
Nature Chemistry Oct 2017Direct C(sp)-C(sp) bond formation under transition-metal-free conditions offers an atom-economical, inexpensive and environmentally benign alternative to traditional...
Direct C(sp)-C(sp) bond formation under transition-metal-free conditions offers an atom-economical, inexpensive and environmentally benign alternative to traditional transition-metal-catalysed cross-coupling reactions. A new chemo- and regioselective coupling protocol between 3-aryl-substituted-1,1-diphenyl-2-azaallyl derivatives and vinyl bromides has been developed. This is the first transition-metal-free cross-coupling of azaallyls with vinyl bromide electrophiles and delivers allylic amines in excellent yields (up to 99%). This relatively simple and mild protocol offers a direct and practical strategy for the synthesis of high-value allylic amine building blocks that does not require the use of transition metals, special initiators or photoredox catalysts. Radical clock experiments, electron paramagnetic resonance studies and density functional theory calculations point to an unprecedented substrate-dependent coupling mechanism. Furthermore, an electron paramagnetic resonance signal was observed when the N-benzyl benzophenone ketimine was subjected to silylamide base, supporting the formation of radical species upon deprotonation. The unique mechanisms outlined herein could pave the way for new approaches to transition-metal-free C-C bond formations.
Topics: Allyl Compounds; Amines; Aza Compounds; Molecular Structure; Stereoisomerism; Transition Elements; Vinyl Compounds
PubMed: 28937664
DOI: 10.1038/nchem.2760 -
Chemical Reviews Aug 2008
Review
Topics: Alkylation; Allyl Compounds; Catalysis; Copper; Crystallography, X-Ray; Models, Molecular; Molecular Structure; Organometallic Compounds; Stereoisomerism
PubMed: 18698733
DOI: 10.1021/cr068424k -
Chemistry (Weinheim An Der Bergstrasse,... Dec 2011
Topics: Allyl Compounds; Catalysis; Molecular Structure; Palladium; Sulfonium Compounds
PubMed: 22095834
DOI: 10.1002/chem.201102937 -
Chemical & Pharmaceutical Bulletin Jan 2002Palladium catalyzed asymmetric allylic alkylations represent a challenging problem because the mechanism of the reaction places the chiral environment distal to the bond... (Review)
Review
Palladium catalyzed asymmetric allylic alkylations represent a challenging problem because the mechanism of the reaction places the chiral environment distal to the bond breaking or making events responsible for the asymmetric induction. Furthermore, unlike virtually every other asymmetric process, many strategies can be employed for introduction of asymmetry and many different types of bonds can be formed. While over 100 different ligands have been designed, a family of ligands derived from 2-diphenylphosphinobenzoic or 1-naphthoic acid and chiral scalemic diamines have been successful in inducing excellent enantioselectivity by five different enantiodiscriminating events. These methods have already provided practical strategies towards numerous biological targets--some of which are adenosine and its enantiomer, aflatoxin B, aristeromycin, calanolide A and B, carbovir, cyclophellitol, ethambutol, galanthamine, mannostatin, neplanocin, phyllanthocin, sphingofungins E and F, tetraponaines, vigabatrin, and valienamine.
Topics: Alkylation; Allyl Compounds; Catalysis; Ligands; Models, Chemical; Palladium; Stereoisomerism; Structure-Activity Relationship
PubMed: 11824567
DOI: 10.1248/cpb.50.1 -
Bioorganic Chemistry Jun 2020In this study, we described the microbial catalyzed allylic oxidation by Bacillus megaterium CGMCC 1.1741 of three Δ-pentacyclic triterpenes, erythrodiol (1), uvaol...
In this study, we described the microbial catalyzed allylic oxidation by Bacillus megaterium CGMCC 1.1741 of three Δ-pentacyclic triterpenes, erythrodiol (1), uvaol (2), hederagenin (3) and of four steroids including Δ-steroids, diosgenin (4), pennogenin (5), 25(R,S)-ruscogenin (6) and Δ-steroid, diosgenone (7). As a result, fourteen metabolites were generated with allyl hydroxyl moiety. Ten (1a-c, 2a, 2c, 3a, 5a-b, and 6a-b) of them were new natural products and their structures were determined on the basis of 1D/2D NMR and HR-MS data. Biocatalytic allylic oxidation by B. megaterium CGMCC 1.1741 is thus a potential non-toxic and efficient alternative method toward metal-mediated oxidation procedures in the synthesis of natural products and medicines.
Topics: Allyl Compounds; Bacillus megaterium; Hydroxylation; Molecular Conformation; Oxidation-Reduction; Steroids; Triterpenes
PubMed: 32315895
DOI: 10.1016/j.bioorg.2020.103826 -
The Journal of Organic Chemistry Mar 2015Allylboronates undergo C-H allylation of unsubstituted or monosubstituted benzoquinone and naphthoquinone substrates. In the case of 2,5- or 2,6-disubstituted quinones...
Allylboronates undergo C-H allylation of unsubstituted or monosubstituted benzoquinone and naphthoquinone substrates. In the case of 2,5- or 2,6-disubstituted quinones addition involving the substituted carbon takes place. Allylation with stereodefined allylboronates occurs with retention of the configuration.
Topics: Allyl Compounds; Boronic Acids; Molecular Structure; Quinones
PubMed: 25728494
DOI: 10.1021/acs.joc.5b00264 -
Organic Letters Nov 2010Alkyl dioxazaborolidines are air-stable and often crystalline organoboranes. A variety of Brønsted acids activate allyl dioxazaborolidines to generate reactive...
Alkyl dioxazaborolidines are air-stable and often crystalline organoboranes. A variety of Brønsted acids activate allyl dioxazaborolidines to generate reactive allyl-transfer reagents in situ. These reagents add to aldehydes and ketones to generate the corresponding alcohols in good yields under mild conditions. The E- and Z-crotyl reagents react diastereoselectively with aldehydes and ketones to produce anti and syn adducts, respectively, a result consistent with a cyclic transition state (type I mechanism).
Topics: Acids; Aldehydes; Allyl Compounds; Aza Compounds; Ketones; Models, Molecular; Molecular Structure
PubMed: 20942379
DOI: 10.1021/ol1020515