By Maretina I. Alexandrovna, Boris I. Ionin, John C. Tebby(auth.)

Acetylene structures current a brand new path to cyclic compounds instead to more conventional equipment hired in classical natural chemistry. The synthesis of cyclic constructions according to acetylene platforms has vital purposes within the formation of nanostructures, clearly happening compounds and chemosensory fabrics for the layout of nonlinear optics, digital and photonic devices.

Alkynes in Cycloadditions offers a latest overview of regioselective synthesis of fragrant and non-aromatic carbocyclic and heterocyclic ring structures established totally on [2+2+2] and [4+2] cycloadditions, and different reactions of acetylenic devices together with enediynes and enyne-allenes.

Topics lined include:

  • New options for the formation of fragrant and polynuclear hydrocarbons in accordance with (Z)-hex-3-en-1,5-diyne and (Z)-hepta-1,2,4-triene-6-yne blocks.
  • One-step synthesis of benzene derivatives, β-substituted naphthalenes and acenes by way of the cycloaromatization of enediynes and enyne-allenes via Bergman, Myers-Saito and Shmittel.
  • Mechanisms of cycloaromatization leading to the formation of fulvene and indene systems.
  • Heterocyclization concerning enyne-carbodiimides.
  • New achievements in classical cycloaddition reactions reminiscent of the Diels-Alder condensation with acetylenic dienophiles and [2+2] cycloadditions with acetylene components

Alkynes in Cycloadditions provides a complete precis of the literature on tools for the synthesis of ring structures from acetylenes for tutorial researchers operating within the fields of natural synthesis, actual natural chemistry, organometallic chemistry, catalysis, fabrics technology, nanomaterials and biochemistry.

Content:
Chapter 1 creation (pages 1–3):
Chapter 2 Regioselective Syntheses of Polysubstituted Benzenes Catalyzed by means of Transition steel Complexes (pages 5–105):
Chapter three Radical Cycloaromatization of structures Containing (Z)‐3‐hexene‐1,5‐diynes and (Z)‐1,2,4‐heptatrien‐6‐ynes and comparable Heteroatomic Blocks (pages 107–231):
Chapter four chosen Cycloaddition and Heterocyclization Reactions with strange Acetylenic and Allenic beginning Compounds (pages 233–247):
Chapter five Concluding comments (pages 249–253):

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Extra info for Alkynes in Cycloadditions

Example text

The reactions gave a complex mixture of products. On the other hand, the reaction with tosyl amides proceeded very effectively. 18) [3, 53]. 52 at room temperature [51]. 53 X = O, S, NTs, CH2. 55a-d a, R1 = R2 = H; b, R1 = CH2OH, R2 = H: 2 R2 R1 2 H 1 S 1 Ph 90-98%, 6:1 2 c, R = Me, R = CO2Et; d, R = OMe, R = Me. 2 STEREOCHEMICAL ASPECT OF INTRAMOLECULAR AND INTERMOLECULAR REACTIONS OF DIYNES WITH MONOALKYNES The reaction of [2+2+2] cycloaddition of acetylenes to form benzene has been known since the mid-nineteenth century.

31 Intramolecular reaction of enediynes. are significantly more active than the neutral ones, and many are unique in the nature of the transformations [64]. 88 containing unsubstituted alkyne branches were chosen for study. 31) [61, 70, 71]. 31). 6, entries 1 and 2). 6 Intramolecular reaction of (E)-enediynes. R1 Z Z' 2 R [Rh(H8-binap)]BF4 DCM, r,t. 6, entries 3–6) [71]. 32). + X Cat. 92 X = N, O, S, Si, Sn, B, P. 1 Nitrogen-Containing Substrates The ynamides are multipurpose synthetic blocks that are very promising reactants in light of this methodology [72, 73].

Cyclization of dipropargyl ether with phenylacetylene in the presence of Wilkinson’s catalyst in toluene gave 4-phenylphthalane (1,3-dihydro2-benzofuran) [52]. The reaction proceeds with a moderate yield (50%). 2, entries 8–16). With internal monoalkynes bearing an electron-withdrawing substituent, the yield is rather low (entry 17, 34%). It should be noted that dipropargyl ether gave yields of 71–84% although the best yields were obtained with N,N-dipropargyl-p-toluenesulfonamide. Obviously, the central atom (N or O) plays an important role in the cyclization.

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