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Search for "stereocenters" in Full Text gives 131 result(s) in Beilstein Journal of Organic Chemistry.
The arene–alkene photocycloaddition
- Ursula Streit and
- Christian G. Bochet
Beilstein J. Org. Chem. 2011, 7, 525–542, doi:10.3762/bjoc.7.61
- , the complexity of the products is considerably increased with respect to that of the reactants, as a new ring and up to four new stereocenters are formed. The first “classical” [2π + 2π] photocycloaddition of benzene was described by Angus and Bryce-Smith in 1959 [7]. However, Ayer, Bradford and Büchi
- stereocenters in a single step from planar achiral starting materials. If substituents are added to the arene and the complexity of the olefin is increased, a great diversity of products can be created. However, not all of these products are accessible via such a photocycloaddition, as many possibilities can be
Graphical Abstract
Scheme 1: Photochemistry of benzene.
Scheme 2: Three distinct modes of photocycloaddition of arenes to alkenes.
Scheme 3: Mode selectivity with respect of the free enthalpy of the radical ion pair formation.
Scheme 4: Photocycloaddition shows lack of mode selectivity.
Scheme 5: Mechanism of the meta photocycloaddition.
Scheme 6: Evidence of biradiacal involved in meta photocycloaddition by Reedich and Sheridan.
Scheme 7: Regioselectivity with electron withdrawing and electron donating substituents.
Scheme 8: Closure of cyclopropyl ring affords regioisomers.
Scheme 9: Endo versus exo product in the photocycloaddition of pentene to anisole [33].
Scheme 10: Regio- and stereoselectivity in the photocycloaddition of cyclopentene with a protected isoindoline....
Scheme 11: 2,6- and 1,3-addition in intramolecular approach.
Scheme 12: Linear and angularly fused isomers can be obtained upon intramolecular 1,3-addition.
Scheme 13: Synthesis of α-cedrene via diastereoselective meta photocycloaddition.
Scheme 14: Asymmetric meta photocycloaddition introduced by chirality of tether at position 2.
Scheme 15: Enantioselective meta photocycloaddition in β-cyclodextrin cavity.
Scheme 16: Vinylcyclopropane–cyclopentene rearrangement.
Scheme 17: Further diversification possibilities of the meta photocycloaddition product.
Scheme 18: Double [3 + 2] photocycloaddition reaction affording fenestrane.
Scheme 19: Total synthesis of Penifulvin B.
Scheme 20: Towards the total synthesis of Lacifodilactone F.
Scheme 21: Regioselectivity of ortho photocycloaddition in polarized intermediates.
Scheme 22: Exo and endo selectivity in ortho photocycloaddition.
Scheme 23: Ortho photocycloaddition of alkanophenones.
Scheme 24: Photocycloadditions to naphtalenes usually in an [2 + 2] mode [79].
Scheme 25: Ortho photocycloaddition followed by rearrangements.
Scheme 26: Stable [2 + 2] photocycloadducts.
Scheme 27: Ortho photocycloadditions with alkynes.
Scheme 28: Intramolecular ortho photocycloaddition and rearrangement thereof.
Scheme 29: Intramolecular ortho photocycloaddition to access propellanes.
Scheme 30: Para photocycloaddition with allene.
Scheme 31: Photocycloadditions of dianthryls.
Scheme 32: Photocycloaddition of enone with benzene.
Scheme 33: Intramolecular photocycloaddition affording multicyclic compounds via [4 + 2].
Scheme 34: Photocycloaddition described by Sakamoto et al.
Scheme 35: Proposed mechanism by Sakamoto et al.
Scheme 36: Photocycloaddition described by Jones et al.
Scheme 37: Proposed mechanism for the formation of benzoxepine by Jones et al.
Scheme 38: Photocycloaddition observed by Griesbeck et al.
Scheme 39: Mechanism proposed by Griesbeck et al.
Scheme 40: Intramolecular photocycloaddition of allenes to benzaldehydes.
Brønsted acid-promoted azide–olefin [3 + 2] cycloadditions for the preparation of contiguous aminopolyols: The importance of disiloxane ring size to a diastereoselective, bidirectional approach to zwittermicin A
- Hubert Muchalski,
- Ki Bum Hong and
- Jeffrey N. Johnston
Beilstein J. Org. Chem. 2010, 6, 1206–1210, doi:10.3762/bjoc.6.138
- particularly intrigued by the possibility of a substrate controlled anti-diastereoselective azide–olefin reaction performed in a bidirectional fashion [13][14] to establish the requisite stereocenters of the C9–C15 C2 symmetric core of the natural product [11] as outlined in Scheme 1. Diastereoselective
Graphical Abstract
Scheme 1: Retrosynthetic analysis outlining the stereocontrolled construction of the aminopolyol core of (−)-...
Scheme 2: Depictions of the likely major conformations of the siloxane (A) and disiloxane (B) rings.
Scheme 3: Confirmation of the relative stereochemistry of bis(triazoline) 14a. (a) TfOH, CH3CN, rt, 18 h; (b)...
Novel tetracyclic structures from the synthesis of thiolactone-isatin hybrids
- Renate Hazel Hans,
- Hong Su and
- Kelly Chibale
Beilstein J. Org. Chem. 2010, 6, No. 78, doi:10.3762/bjoc.6.78
- in the tetracycles 4 was further sparked by the ease and simplicity of their preparation, and the novelty of their architecture as revealed by single X-ray crystal structure analysis. Attractive structural features of 4 include two vicinal quaternary stereocenters and a complex, bicyclic ring system
Graphical Abstract
Figure 1: Natural product and natural product-like hybrids.
Figure 2: Structures of thiolactomycin (1), isatin (2), the desired hybrid 3 and tetracycle 4.
Scheme 1: Reagents and conditions: (a) KOH, MeOH, 25 °C, 95–100% (b) 6, DMF, 60 °C, 9–36%.
Scheme 2: Proposed mechanism for the formation of tetracycles 4.
Figure 3: (a) Molecular structure of the tetracycle 4a. (b) Structure of the dimer of 4a showing the atomic n...
Figure 4: Molecular structure of (a) 4b and (b) 4c, with ellipsoidal model of probability level = 35%.
Recent advances in carbocupration of α-heterosubstituted alkynes
- Ahmad Basheer and
- Ilan Marek
Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77
- stereocenters (Scheme 10) [23]. Sulfonyl-substituted ynamide 22 has also been investigated in carbocupration and copper-catalyzed carbomagnesiation reactions (Scheme 11) [22]. Irrespective of the conditions, the carbometalation reaction on sulfonyl-substituted ynamide 22 is slower than that with ynamide 17. In
Graphical Abstract
Scheme 1: General scheme for the carbocupration reaction.
Scheme 2: Regioselectivity in the carbocupration reaction.
Scheme 3: Carbocupration of α-alkoxyalkynes.
Scheme 4: Carbocupration of substituted α-alkoxyalkynes.
Scheme 5: Formation of the branched isomer.
Scheme 6: Formation of the linear isomer.
Scheme 7: Carbocupration of O-alkynyl carbamates.
Scheme 8: Carbocupration of ynamines.
Scheme 9: Carbocupration of ynamide.
Scheme 10: Formation of aldol products possessing stereogenic quaternary carbon centers.
Scheme 11: Carbocupration of alkynyl sulfonamide.
Scheme 12: Tandem carbocupration-sigmatropic rearrangement.
Scheme 13: Silylcupration of alkynyl sulfonamides.
Scheme 14: Carbocupration of P-substituted alkynes.
Scheme 15: Carbocupration of alkynylphosphonates.
Scheme 16: Carbocupration of thioalkynes.
Scheme 17: Tandem carbocupration-1,2-metalate rearrangement.
Scheme 18: Carbocupration with functionalized organocopper species.
Scheme 19: Carbocupration of alkynyl sulfoxides.
Scheme 20: Carbocupration of alkynyl sulfones.
Scheme 21: Carbocupration of alkynyl sulfoximines.
Scheme 22: Carbocupration of alkynylsilanes.
Scheme 23: Carbocupration of functionalized alkynylsilanes.
Scheme 24: Silyl- and stannyl cupration of silyl- and stannylalkynes.
A short stereoselective synthesis of (+)-(6R,2′S)-cryptocaryalactone via ring- closing metathesis
- Palakodety Radha Krishna,
- Krishnarao Lopinti and
- K. L. N. Reddy
Beilstein J. Org. Chem. 2009, 5, No. 14, doi:10.3762/bjoc.5.14
- wherein a chiral 2,3-epoxy alcohol was the starting material and Sharpless asymmetric epoxidation and Carreira asymmetric alkynylation were used as key steps for generating unambiguous assigned stereocenters. More importantly, the Grubbs’ ring-closing metathesis protocol was applied to construct the final
Graphical Abstract
Figure 1: Some natural products containing styryl lactones.
Figure 2: Retrosynthetic approach.
Scheme 1: Synthesis of chiral propargyl secondary hydroxyl group.
Scheme 2: Determination of the stereochemistry of the 1,3-anti diols.
Scheme 3: Synthesis of cryptocaryalactone by RCM.
Recent progress on the total synthesis of acetogenins from Annonaceae
- Nianguang Li,
- Zhihao Shi,
- Yuping Tang,
- Jianwei Chen and
- Xiang Li
Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48
- (2S)-10,2-camphorsultam. The key oxidative cyclization reaction, conducted under phase-transfer conditions, introduced the C15, C16, C19, and C20 stereocenters present in cis-solamin in one step, then the auxiliary was best removed from 79 by reduction using NaBH4. The resulting diol was taken forward
- acetogenins contains six oxygenated stereocenters, and much of the synthetic work on the family has been focused in that direction. The first successful approach was recorded in 1991 by Hoye’s group who employed a two-directional inside-out epoxide cascade sequence to prepare a core enantiomer of uvaricin [66
Graphical Abstract
Scheme 1: Total synthesis of longifolicin by Marshall’s group.
Scheme 2: Total synthesis of corossoline by Tanaka’s group.
Scheme 3: Total synthesis of corossoline by Wu’s group.
Scheme 4: Total synthesis of pseudo-annonacin A by Hanessian’s group.
Scheme 5: Total synthesis of tonkinecin by Wu’s group.
Scheme 6: Total synthesis of gigantetrocin A by Shi’s group.
Scheme 7: Total synthesis of annonacin by Wu’s group.
Scheme 8: Total synthesis of solamin by Kitahara’s group.
Scheme 9: Total synthesis of solamin by Mioskowski’s group.
Scheme 10: Total synthesis of cis-solamin by Makabe’s group.
Scheme 11: Total synthesis of cis-solamin by Brown’s group.
Scheme 12: The formal synthesis of (+)-cis-solamin by Donohoe’s group.
Scheme 13: Total synthesis of cis-solamin by Stark’s group.
Scheme 14: Total synthesis of mosin B by Tanaka’s group.
Scheme 15: Total synthesis of longicin by Hanessian’s group.
Scheme 16: Total synthesis of murisolin and 16,19-cis-murisolin by Tanaka’s group.
Scheme 17: Synthesis of a stereoisomer library of (+)-murisolin by Curran’s group.
Scheme 18: Total synthesis of murisolin by Makabe’s group.
Scheme 19: Total synthesis of reticulatain-1 by Makabe’s group.
Scheme 20: Total synthesis of muricatetrocin C by Ley’s group.
Scheme 21: Total synthesis of (4R,12S,15S,16S,19R,20R,34S)-muricatetrocin (146) and (4R,12R,15S,16S,19R,20R,34S...
Scheme 22: Total synthesis of parviflorin by Hoye’s group.
Scheme 23: Total synthesis of parviflorin by Trost’s group.
Scheme 24: Total synthesis of trilobacin by Sinha’s group.
Scheme 25: Total synthesis of 15-epi-annonin I 181b by Scharf’s group.
Scheme 26: Total synthesis of squamocin A and squamocin D by Scharf’s group.
Scheme 27: Total synthesis of asiminocin by Marshall’s group.
Scheme 28: Total synthesis of asiminecin by Marshall’s group.
Scheme 29: Total synthesis of (+)-(30S)-bullanin by Marshall’s group.
Scheme 30: Total synthesis of uvaricin by the group of Sinha and Keinan.
Scheme 31: Formal synthesis of uvaricin by Burke’s group.
Scheme 32: Total synthesis of trilobin by Marshall’s group.
Scheme 33: Total synthesis of trilobin by the group of Sinha and Keinan.
Scheme 34: Total synthesis of asimilobin by the group of Wang and Shi.
Scheme 35: Total synthesis of squamotacin by the group of Sinha and Keinan.
Scheme 36: Total synthesis of asimicin by Marshall’s group.
Scheme 37: Total synthesis of asimicin by the group of Sinha and Keinan.
Scheme 38: Total synthesis of asimicin by Roush’s group.
Scheme 39: Total synthesis of asimicin by Marshall’s group.
Scheme 40: Total synthesis of 10-hydroxyasimicin by Ley’s group.
Scheme 41: Total synthesis of asimin by Marshall’s group.
Scheme 42: Total synthesis of bullatacin by the group of Sinha and Keinan.
Scheme 43: Total synthesis of bullatacin by Roush’s group.
Scheme 44: Total synthesis of bullatacin by Pagenkopf’s group.
Scheme 45: Total synthesis of rollidecins C and D by the group of Sinha and Keinan.
Scheme 46: Total synthesis of 30(S)-hydroxybullatacin by Marshall’s group.
Scheme 47: Total synthesis of uvarigrandin A and 5(R)-uvarigrandin A by Marshall’s group.
Scheme 48: Total synthesis of membranacin by Brown’s group.
Scheme 49: Total synthesis of membranacin by Lee’s group.
Scheme 50: Total synthesis of rolliniastatin 1 and rollimembrin by Lee’s group.
Scheme 51: Total synthesis of longimicin D by the group of Maezaki and Tanaka.
Scheme 52: Total synthesis of the structure proposed for mucoxin by Borhan’s group.
Scheme 53: Modular synthesis of adjacent bis-THF annonaceous acetogenins by Marshall’s group.
Scheme 54: Total synthesis of 4-deoxygigantecin by Tanaka’s group.
Scheme 55: Total synthesis of squamostatins D by Marshall’s group.
Scheme 56: Total synthesis of gigantecin by Crimmins’s group.
Scheme 57: Total synthesis of gigantecin by Hoye’s group.
Scheme 58: Total synthesis of cis-sylvaticin by Donohoe’s group.
Scheme 59: Total synthesis of 17(S),18(S)-goniocin by Sinha’s group.
Scheme 60: Total synthesis of goniocin and cyclogoniodenin T by the group of Sinha and Keinan.
Scheme 61: Total synthesis of jimenezin by Takahashi’s group.
Scheme 62: Total synthesis of jimenezin by Lee’s group.
Scheme 63: Total synthesis of jimenezin by Hoffmann’s group.
Scheme 64: Total synthesis of muconin by Jacobsen’s group.
Scheme 65: Total synthesis of (+)-muconin by Kitahara’s group.
Scheme 66: Total synthesis of muconin by Takahashi’s group.
Scheme 67: Total synthesis of muconin by the group of Yoshimitsu and Nagaoka.
Scheme 68: Total synthesis of mucocin by the group of Sinha and Keinan.
Scheme 69: Total synthesis of mucocin by Takahashi’s group.
Scheme 70: Total synthesis of (−)-mucocin by Koert’s group.
Scheme 71: Total synthesis of mucocin by the group of Takahashi and Nakata.
Scheme 72: Total synthesis of mucocin by Evans’s group.
Scheme 73: Total synthesis of mucocin by Mootoo’s group.
Scheme 74: Total synthesis of (−)-mucocin by Crimmins’s group.
Scheme 75: Total synthesis of pyranicin by the group of Takahashi and Nakata.
Scheme 76: Total synthesis of pyranicin by Rein’s group.
Scheme 77: Total synthesis of proposed pyragonicin by the group of Takahashi and Nakata.
Scheme 78: Total synthesis of pyragonicin by Rein’s group.
Scheme 79: Total synthesis of pyragonicin by Takahashi’s group.
Scheme 80: Total synthesis of squamostanal A by Figadère’s group.
Scheme 81: Total synthesis of diepomuricanin by Tanaka’s group.
Scheme 82: Total synthesis of (−)-muricatacin [(R,R)-373a] and its enantiomer (+)-muricatacin [(S,S)-373b] by ...
Scheme 83: Total synthesis of epi-muricatacin (+)-(S,R)-373c and (−)-(R,S)-373d by Scharf’s group.
Scheme 84: Total synthesis of (−)-muricatacin 373a and 5-epi-(−)-muricatacin 373d by Uang’s group.
Scheme 85: Total synthesis of four stereoisomers of muricatacin by Yoon’s group.
Scheme 86: Total synthesis of (+)-muricatacin by Figadère’s group.
Scheme 87: Total synthesis of (+)-epi-muricatacin and (−)-muricatacin by Couladouros’s group.
Scheme 88: Total synthesis of muricatacin by Trost’s group.
Scheme 89: Total synthesis of (−)-(4R,5R)-muricatacin by Heck and Mioskowski’s group.
Scheme 90: Total synthesis of muricatacin (−)-373a by the group of Carda and Marco.
Scheme 91: Total synthesis of (−)- and (+)-muricatacin by Popsavin’s group.
Scheme 92: Total synthesis of (−)-muricatacin by the group of Bernard and Piras.
Scheme 93: Total synthesis of (−)-muricatacin by the group of Yoshimitsu and Nagaoka.
Scheme 94: Total synthesis of (−)-muricatacin by Quinn’s group.
Scheme 95: Total synthesis of montecristin by Brückner’s group.
Scheme 96: Total synthesis of (−)-acaterin by the group of Franck and Figadère.
Scheme 97: Total synthesis of (−)-acaterin by Singh’s group.
Scheme 98: Total synthesis of (−)-acaterin by Kumar’s group.
Scheme 99: Total synthesis of rollicosin by Quinn’s group.
Scheme 100: Total synthesis of Rollicosin by Makabe’s group.
Scheme 101: Total synthesis of squamostolide by Makabe’s group.
Scheme 102: Total synthesis of tonkinelin by Makabe’s group.
