68900-87-8Relevant articles and documents
Cationic Co(I)-intermediates for hydrofunctionalization reactions: Regio- A nd enantioselective cobalt-catalyzed 1,2-hydroboration of 1,3-dienes
Duvvuri, Krishnaja,Dewese, Kendra R.,Parsutkar, Mahesh M.,Jing, Stanley M.,Mehta, Milauni M.,Gallucci, Judith C.,Rajanbabu
supporting information, p. 7365 - 7375 (2019/05/16)
Much of the recent work on catalytic hydroboration of alkenes has focused on simple alkenes and styrene derivatives with few examples of reactions of 1,3-dienes, which have been reported to undergo mostly 1,4-additions to give allylic boronates. We find that reduced cobalt catalysts generated from 1,n-bis-diphenylphosphinoalkane complexes [Ph2P-(CH2)n-PPh2]CoX2; n = 1-5) or from (2-oxazolinyl)phenyldiarylphosphine complexes [(G-PHOX)CoX2] (G = 4-substituent on oxazoline ring) effect selective 1,2-, 1,4-, or 4,3-additions of pinacolborane (HBPin) to a variety of 1,3-dienes depending on the ligands chosen. Conditions have been found to optimize the 1,2-additions. The reactive catalysts can be generated from the cobalt(II)-complexes using trimethylaluminum, methyl aluminoxane, or activated zinc in the presence of sodium tetrakis[(3,5-trifluoromethyl)phenyl]borate (NaBARF). The complex, (dppp)CoCl2, gives the best results (ratio of 1,2-to 1,4-addition >95:5) for a variety of linear terminal 1,3-dienes and 2-substituted 1,3-dienes. The [(PHOX)CoX2] (X = Cl, Br) complexes give mostly 1,4-addition with linear unsubstituted 1,3-dienes, but, surprisingly, selective 1,2-additions with 2-substituted or 2,3-disubstituted 1,3-dienes. Isolated and fully characterized (X-ray crystallography) Co(I)-complexes, (dppp)3Co2Cl2 and [(S,S)-BDPP]3Co2Cl2, do not catalyze the reaction unless activated by a Lewis acid or NaBARF, suggesting a key role for a cationic Co(I) species in the catalytic cycle. Regio- A nd enantioselective 1,2-hydroborations of 2-substituted 1,3-dienes are best accomplished using a catalyst prepared via activation of a chiral phosphinooxazoline-cobalt(II) complex with zinc and NaBARF. A number of common functional groups, among them,-OBn,-OTBS,-OTs, N-phthalimido-groups, are tolerated, and er's > 95:5 are obtained for several dienes including 1-alkenylcycloalk-1-enes. This operationally simple reaction expands the realm of asymmetric hydroboration to provide direct access to a number of nearly enantiopure homoallylic boronates, which are not readily accessible by current methods. The resulting boronates have been converted into the corresponding alcohols, potassium trifluororoborate salts, N-BOC amines, and aryl derivatives by C-BPin to C-aryl transformation.
Influence of the chemical structure on odor qualities and odor thresholds in homologous series of alka-1,5-dien-3-ones, alk-1-en-3-ones, alka-1,5-dien-3-ols, and alk-1-en-3-ols
Lorber, Katja,Schieberle, Peter,Buettner, Andrea
, p. 1025 - 1031 (2014/03/21)
Odor qualities and odor thresholds in air in homologous series of synthesized alk-1-en-3-ols and alka-1,5-dien-3-ols and their corresponding ketones were evaluated by gas chromatography-olfactometry. In the series of the alk-1-en-3-ols and alk-1-en-3-ones the odor quality changed successively from pungent for the compounds with five carbon atoms via metallic, vegetable-like for the six- and seven-carbon odorants to mushroom-like for the compounds with eight and nine carbon atoms. With further increase in chain length the mushroom-like impression decreased and changed to citrus-like, soapy, or herb-like. In both series, two odor threshold minima were found for the six-carbon and also for the eight- and nine-carbon odorants, respectively. In contrast to this, the odor qualities in the series of the (Z)- and (E)-alka-1,5-dien-3-ols and their corresponding ketones did not change significantly with geranium-like, metallic odors and an increasing mushroom-like odor note with increasing chain length. The lowest thresholds were found for the eight- and nine-carbon (Z)-compounds, respectively.
Influence of the chemical structure on odor qualities and odor thresholds in homologous series of alka-1,5-dien-3-ones, alk-1-en-3-ones, alka-1,5-dien-3-ols, and alk-1-en-3-ols
Lorber, Katja,Schieberle, Peter,Buettner, Andrea
, p. 1025 - 1031 (2015/04/22)
Odor qualities and odor thresholds in air in homologous series of synthesized alk-1-en-3-ols and alka-1,5-dien-3-ols and their corresponding ketones were evaluated by gas chromatography-olfactometry. In the series of the alk-1-en-3-ols and alk-1-en-3-ones the odor quality changed successively from pungent for the compounds with five carbon atoms via metallic, vegetable-like for the six- and seven-carbon odorants to mushroom-like for the compounds with eight and nine carbon atoms. With further increase in chain length the mushroom-like impression decreased and changed to citrus-like, soapy, or herb-like. In both series, two odor threshold minima were found for the six-carbon and also for the eight- and nine-carbon odorants, respectively. In contrast to this, the odor qualities in the series of the (Z)- and (E)-alka-1,5-dien-3-ols and their corresponding ketones did not change significantly with geranium-like, metallic odors and an increasing mushroom-like odor note with increasing chain length. The lowest thresholds were found for the eight- and nine-carbon (Z)-compounds, respectively.
Synthesis and biological evaluation of γ-fluoro-β,γ-unsaturated acids
Asakura, Noriaki,Usuki, Yoshinosuke,Iio, Hideo,Tanaka, Toshio
, p. 800 - 808 (2008/03/28)
Several γ-fluoro-β,γ-unsaturated acids, fluorine-containing analogues of N-acyl glycines, were synthesized via Julia-Lythgoe olefination. The antimicrobial activities of these compounds and synthetic intermediates were evaluated. Analogues with an octyl group showed in vitro antifungal activity agaist Penicillium chrysogenum IFO4626.
Short and stereoselective synthesis of (E)-3-alkenyl acetates, insect sex pheromone constituents of Lepidoptera; Gelechidae
Ragoussis, Valentine,Vamvaka, Ekaterini,Kolymbadi, Maria
, p. 398 - 399 (2007/10/03)
(E)-3-alkenyl acetates, which are insect sex pheromone constituents, have been prepared from linear saturated aldehydes, by a short three steps process, via the (E)-3-alkenoic acids and the corresponding (E)-3-alkenols, in good overall yield (60-65%) and high stereochemical purity (>99%).
Two approaches for the synthesis of sweet potato weevil and sugar beet moth pheromones
Pawar, A. S.,Chattopadhyay, S.,Mamdapur, V. R.
, p. 463 - 464 (2007/10/02)
Two approaches for the synthesis of (3Z)- and (3E)-dodecenols, the important precursors of several important pheromones have been developed based on acetylene chemistry and modified Knovenagel condensation.The key features of the approaches are use of inexpensive chemicals and simple reaction conditions.The alcohols are converted to the title pheromones by suitable functionalisation.
Metal/Ammonia Reduction of Ethers of 3-Decyn-1-ol: Effects of Structure and Conditions on Cleavage and Rearrangement
Doolittle, Robert E.,Patrick, Delrea G.,Heath, Robert H.
, p. 5063 - 5066 (2007/10/02)
Reduction of the THP, ethyl, tert-butyl and tert-butyldimethylsilyl (TBDMS) ethers of 3-decyn-1-ol with sodium in ammonia/THF results in extensive hydrogenolysis of the carbon-oxygen bond and concomitant bond migration, producing a mixture of 2- and 3-decenes and a very low yield of the desired (E)-homoallylic ether.Reduction in the presence of 2-methyl-2-propanol led to excellent yields of the desired (E)-3-decenol ethers.The 4- and 5-decyn-1-ol ethers were reduced normally to the (E)-decen-1-ol ethers except in the case of the TBDMS ethers which were cleaved to the (E)-alcohols under some of the reaction conditions.
SYNTHESIS OF DODEC-5E-EN-1-OL - THE PHEROMONE OF TRICIMBA CINCTA - AND TETRADEC-5E-1-YL ACETATE - AN IMITATOR OF THE PHEROMONE OF RHYNCHOPACHA SP.
Verba, G. G.,Bukulova, L. M.,Abduvakhabov, A. A.,Kamaev, F. G.
, p. 113 - 116 (2007/10/02)
On the basis of a modified Knoevenagel reaction starting from octanal and decanal, the stereodirected synthesis has been effected of dodec-5E-en-ol (the pheromone of the grass fly Tricimba cincta - and tetradec-5E-en-yl acetate) an imitator of the pheromone of the moth Rhynchopacha sp.
SYNTHESIS OF (E)-DODEC-3-EN-1-YL ACETATE - THE MAIN COMPONENT OF SEX PHEROMONES OF Scrobipalpa ocellatella AND Scrobipalpopsis solanivora
Bikulova, L. M.,Verba, G. G.,Kamaev, F. G.,Abduvakhabov, A. A.
, p. 580 - 581 (2007/10/02)
(E)-Dodec-3-en-1-yl acetate - the main component of the sex pheromones of Scrobipalpa ocellatella and Scrobipalpopsis solanivora - has been obtained by a three-stage synthesis from decanal and malonic acid.The overall yield of pheromone was 33percent calculated on the initial aldehyde.
Syntheses of Monounsaturated Sex Pheromones of Lepidoptera via 3-Alkyn-1-ols
Pop, Lidia,Oprean, I.,Barabas, A.,Hodosan, F.
, p. 867 - 878 (2007/10/02)
3-Alkyn-1-ols as intermediate synthons in the preparation of some Lepidoteran sex pheromones were utilized.Characteristic fragmentations reflecting the position of the triple bond were found in the mass spectra of 3-alkyn-1-ols and alkyn-1-yl acetates in contrast to 1-tert-butoxy-alkynes.A partial isomerization of 1-tosyloxy-3-(Z)-octene to 1-bromo-3-(E)-octene within the reaction with NaBr in DMF was noticed by GC and 13C-n.m.r., for which a mechanism involving homoconjugation in an intermediate non-classical carbonium ion was suggested.
