Photocyclization of 1,2-diarylethylenes in primary amines. A convenient method for the synthesis of dihydro aromatic compounds and a means of reducing the loss of methyl groups during the cyclization of o-methylstilbenes

Lapouyade, R.; Veyres, Alain; Hanafi, N.; Couture, Axel; Lablache‐Combier, A.

doi:10.1021/jo00346a045

Cited by 27 publications

(12 citation statements)

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“…The amine-mediated 1,3-H-shift discovered with the photocyclization of 1-(~-styryl)naphthalene has been extended to the photochemical syntheses of dihydro PAH from 1,2-diarylethylenes (Lapouyade et al 1982b). From stilbene the predominant product is 1,4-dihydrophenanthrene (Couture et al 1975) while larger diarlethylenes give only compounds analogous to 9,10-dihydrophenanthrcne.…”

Section: Photocyclization Of 12-diarylethylenes In Primary Aminesmentioning

confidence: 99%

“…There is an overwhelming amount of literature, recently surveyed (Laarhoven 1983;Mallory and Mallory 1984;Liu et al 1991), on the photocyclodehydrogenation of 1,2-diarylethylenes (stilbene-like) into angularly fused PAH (phenanthrene-like). We discovered the photocyclization of ~-arylolefins, made chemically efficient by amine-induced proton tautomerism in the primary photoproduct (Lapouyade et al 1977), and extended this base-mediated 1,3-H-shift to the photocyclization of 1,2-diarylethylenes, leading to dihydro PAH (Lapouyade et al 1982b). We also investigated the cyclization of the 2-vinylbiphenyls (VB) from the singlet and the triplet excited states and from the radical cations (Lapouyade et al 1975(Lapouyade et al , 1985(Lapouyade et al , 1987Fornier de Violet et al 1982).…”

Section: Introductionmentioning

confidence: 99%

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Photocyclization of arylethylenes: Mechanism and scope of the reactions

Lapouyade

1993

J Chem Sci

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The photocyclization of three structural types of arylethylenes is systematically investigated in order to provide new pathways to regiospecifically substituted and/or partially hydrogenated polycyclic aromatic hydrocarbons. The scope of the photoformation of acenaphthenes from ~t-arylotefins, in amine solutions, is discussed: when the double bond is acyclic, only the naphthyl and the pyrenyl derivatives are photoreactive, but when the double bond is in a cycle, all the compounds which lead to the trans double bond photocyclize. The amine-mediated 1,3-H-shift, discovered with the preceding series, also occurs with 4a,4b-dihydrophenanthrene, formed by irradiation of 1,2-diarylethylenes, and leads to dihydrophenanthrenes. The photocyclization of 2-vinylbiphenyls is stereoselective from the singlet excited state but not from the triplet, where a fast equilibrium between E and Z configurations precedes the adiabatic cyclization. The radical cation of 2-vinylbiphenyls cyclizes to a phenanthrene radical cation which initiates a protic catalysis to the related fluorenes or, in presence of 2,6-di-t-butypyridine or water, leads stoichiometrically to phenanthrenes.

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Section: Photocyclization Of 12-diarylethylenes In Primary Aminesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Photocyclization of arylethylenes: Mechanism and scope of the reactions

Lapouyade

1993

J Chem Sci

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“…In another example, photolysis of diarylethenes containing a methyl group at the ring-closing position led to the formation of trithia[5]helicene derivatives (thiophene isostere of phenanthrene) by formal abstraction of the methane molecule (cleavage of a strong C–C bond) due to photoinduced electron-transfer (PET) reaction . However, this is not the only case of methyl group cleavage; other examples have also been reported in recent works …”

Section: Introductionmentioning

confidence: 99%

Photocyclization of Diarylethenes: The Effect of Electron and Proton Acceptors as Additives

et al. 2021

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The effect of electron and proton acceptors on the photocyclization of diarylethenes has been studied. Without any additives, the deprotonation reaction is predominant, although other processes, including the sigmatropic shift, are not excluded. A deuterium exchange experiment has shown that a strong base (DABCO) facilitates the deprotonation reaction, thereby limiting the sigmatropic shift. In the presence of an oxidizing agent or additional sources of radicals (O2, I2, TEMPO), the processes of deprotonation and rearrangement (H-shift) are practically not observed, and the reaction proceeds along a radical pathway with the formation of phenanthrene or its heterocyclic analogue.

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“…The general procedure for radical cyclization8 was followed by using the above selenide 9 (93 mg, 0.248 mmol) in benzene (20 mL), PhgSnH (105 #tL, 144 mg, 0.411 mmol) in benzene (10 mL), and AIBN (8 mg, 0.048 mmol) in benzene (10 mL). Flash chromatography of the crude product over silica gel (1 x 15 cm) with 3:2 EtOAc-hexane gave 5 (45 mg, 83%) as a homogeneous ( NMR, 400 MHz) oil: FT-IR (CHC13 cast) 1709 cm"1; NMR (CDC13,400 MHz) 1.04 (d, J = 6.3 Hz, 3 ), 1.54-1.64 (m, 1 H), 1.65-1.75 (m, 1 ), 1.88-2.03 (m, 2 H), 2.34-2.39 (m, 2 H), 2.46 (q, J = 8. 3 Hz, 1 H), 2.57 (dd, J = 6.5, 2.8 Hz, 2 ), 2.91-3.02 (m, 2 H), 4.45 (dd, J = 6.5, 2.3 Hz, 1 ), 6.70 (s, 1 H), 7.22 (s, 1 H), 7.38 Found: C, 71.15; H, 7.72; N, 6.53. (5a,7a,8a,8aa)-(±)-5-(3-Furyl)octahydro-8-methyl-7indolizinol (10).…”

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confidence: 99%

“…A solution of PhSeCN (66 mg, 0.360 mmol) in THE (1.5 mL) was added over 15 min to a refluxing solution of 10 (40 mg, 0.181 mmol) and Bu3P (73 mg, 0.360 mmol) in THE (2 mL), and refluxing was continued for a further 1.5 h. The solvent was then evaporated, and flash chromatography of the residue over silica gel (1 X 15 cm) with 2:5 EtOAc-hexane gave 11 (41 mg, 63%) as a homogeneous ( NMR, 400 MHz) oil: NMR (CDC13, 400 MHz) 1.18 (d, J = 7.0 Hz, 3 ), 1.35-1.55 (m, 3 ), 1.70-1.810 (m, 1 ), 1.89-1.98 (m, 1 ), 2.17-2.33 (m, 3 H), 2.36 (q, J = 8. 3 Hz, 1 H), 2.78 (td, J = 6.0, 3.6 Hz, 1 H), 3.12 (td, J = 8.2,5.0 Hz, 1 ), 4.12 (dd, J = 8.3,3.6 Hz, 1 H), 6.27 (s, 1 ), 7.20-7.30 (m, 4 H), 7.36 (s, 1 ), 7.50-7.55 (5a,8a,8aa)-(±)-5-(3-Furyl)octahydro-8-methylindolizine (2). A solution of selenide 11 (32 mg, 0.089 mmol), Ph3SnH (134 µL, 47 mg, 0.133 mmol), and AIBN (4 mg, 0.024 mmol) in benzene (10 mL) was refluxed for 2 h. Evaporation of the solvent and flash chromatography of the residue over silica gel (1 x 15 cm) with 1:1 EtOAc-hexane gave 2 (18 mg, 99%) as a homogeneous (*H NMR, 400 MHz) oil: NMR (CDC13, 400 MHz) 0.93 (d, J = 6.4 Hz, 3 ), 1.22-1.42 (m, 3 ), 1.48-1.69 (m, 1 ), 1.62-1.93 (m, 4 ), 2.00-2.10 (m, 2 H), 2.29 (q, J = 8.…”

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confidence: 99%