Iridium Complex‐Catalyzed [2 + 2 + 2] Cycloaddition of α,ω‐Diynes with Monoynes and Monoenes.

Abstract

Cycloaddition reactions O 0070Iridium Complex-Catalyzed [2 + 2 + 2] Cycloaddition of α,ω-Diynes with Monoynes and Monoenes. -A detailed account on the recently published Ir-catalyzed cycloaddition of diynes with monoalkynes is presented and extended by monoalkenes as addition partners. In some of the reactions using monoalkenes, a novel aromatization of initial formed cyclohexadiene derivatives is observed. A ligand-controlled switch in regioselectivity is discovered in the reactions of 1,6-octadiene derivative (XII) with terminal alkynes. -(KEZUKA, S.; TANAKA, S.; OHE, T.; NAKAYA, Y.; TAKEUCHI*, R.; J. Org. Chem. 71 (2006) 2, 543-552; Dep. Chem. Biol. Sci., Aoyama Gakuin Univ., Sagamihara 229, Japan; Eng.) -Nuesgen 23-028

Synthesis of 2-Sulfonyl Indenes and Indanes

“…To study the substrate scope of A-15 mediated Knoevenagel condensation, substituted 5 and 6 were reacted in toluene to afford diversified 4 by the optimal conditions established (Table 1, entry 16). As shown in Table 2, the facile formation of 4a−4ai showed that the R and Ar′ substituents of 5a−5p and the Ar substituent of 6a−6y did not influence the yield (entries 1−41).…”

“…Therefore, the incorporation of the sulfonyl group into organic molecules is an important task. 21−27 In Scheme 1, the typical routes for the synthesis of 2-sulfonyl indanes and indenes include: (i) oxidation of 2-indanyl phenyl sulfide, 15 (ii) Ir + catalyzed [2 + 2 + 2] cycloaddition of sulfonyl diyne and monoyne, 16 (iii) base-mediated conjugation of tosylmethyl isocyanide (TosMIC) and 2-bromobenzyl bromide, 17 (iv) Cu + promoted sulfonylation of indene with dimethyl sulfoxide in the presence of an oxygen atmosphere, 18 (v) Pd 2+ promoted remote ortho C−H alkenylation of arylethyl 2-pyridyl sulfone followed by base mediated intramolecular ring-closure, 19 and (vi) electrooxidative tandem cyclization of activated alkynes with sulfinic acid. 20 Although diversified routes have been described to construct sulfonyl indanes or indenes, it still remains challenging to explore a facile and highyield method in the formation of this core system.…”

“…Single-crystal X-ray diagram: crystal of 4n was grown by slow diffusion of EtOAc into a solution of 4n in CH 2 Cl 2 to yield colorless prisms. The compound crystallizes in the monoclinic crystal system, space group P2 1 /n, a = 14.5709(16) Å, b = 8.0748(8) Å, c = 18.602(2) Å, V = 2188.3(4) Å3 , Z = 4, d calcd = 1.331 g/cm3 , F(000) = 920, 2θ range 1.760−26.369°, R indices (all data) R1 = 0.0575, wR2 = 0.151.1-Phenyl-2-(toluene-4-sulfonyl)-3-p-tolylpropenone (4o). 4o was synthesized according to general synthetic procedure from 5a (137 mg, 0.5 mmol) and 6o (72 mg, 0.6 mmol).…”

“…FO 4 S 413.1223, found 413.1225;1 H NMR (400 MHz, CDCl 3 ) δ 7.85−7.80 (m, 2H), 7.21−7 16. (m, 3H), 7.13−7.07 (m, 2H), 6.90−6.87 (m, 2H), 6.73 (s, 1H), 6.31 (s, 1H), 4.77 (d, J = 6.0 Hz, 1H), 3.99 (dt, J = 6.0, 9.2 Hz, 1H), 3.85 (s, 3H), 3.67 (s, 3H), 3.51 (dd, J = 6.0, 16 4.…”