Rhodium catalysed [2+2+2] cycloadditions of acetylenes

Grigg, Ronald; Scott, Ronald M.; Stevenson, Paul J.

doi:10.1016/s0040-4039(00)87433-x

Cited by 108 publications

(31 citation statements)

References 11 publications

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“…Catalytic cyclotrimerization of 3α and 3β with 1,7-octadiyne was also attempted but it did not provide the expected products. This observation is not wholly surprising because similar results has been observed before by others [17] and also by us [3a] and could be best explained by the Thorpe-Ingold effect. [18] In these cases the unreacted starting material was detected in the 40-45% range.…”

Section: Resultssupporting

confidence: 90%

Cycloaddition Reactions of Deoxyribosylpropynoates

Hessler

Kulhavá

Císarˇová

et al. 2014

Synthetic Communications

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GRAPHICAL ABSTRACTAbstract Pure anomers of either α or β 3-(2-deoxyribofuranosyl)propynoates reacted with the tetramethylcyclobutadiene-aluminum trichloride complex to yield the corresponding diastereoisomeric Dewar benzenes. Thermal-or ultraviolet light-initiated rearrangement gave rise to highly substituted C-aryldeoxyribosides as single anomers. The same compounds as well as other substituted deoxyribosides were obtained also by transition metal-mediated cycloaddition reactions.

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Section: Resultssupporting

confidence: 90%

Cycloaddition Reactions of Deoxyribosylpropynoates

Hessler

Kulhavá

Císarˇová

et al. 2014

Synthetic Communications

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“…The mixture was refluxed for 2 h. Excess LiAIH, was decomposed by addition of 50 g of ice. Workup yielded 19 (8. (7,heptane -3,4-di~~l)dimethyl Bisjinethanesulfonatej (20) [3] [15]. MsCl (4.7 g, 58.5 mmol) in CH2CI2 (20 ml) was added slowly to a stirred soln.…”

Section: Experimental Partmentioning

confidence: 99%

“…110". [7]. A mixture of diethyl malonate (1.0 g, 6.3 mmol), 21 (2.2 g, 6.3 mmol) and K2C0, (5.0 g) in butan-I-one (50 ml) was refluxed for I2 h. It was then filtered, and the filtrate was concentrated.…”

Section: 4-bis(bromomethyl)-77-dichlnrobicyclo[4l~]hept-3-ene (21)mentioning

confidence: 99%

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Synthesis of Functionalized Cycloprop[f]indenes via the Carbene Addition Route

Müller¹,

Miao²

1994

Helvetica Chimica Acta

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The synthesis of4,5-dihydro-1H,3H-cycloprop[flinden-4-ol (I) and diethyl4,S-dihydro-1 H,3H-cycloprop[flindene-4,4-dicarboxylate (26) starting from dime 4 is described. The cyclopentene ring is constructed by condensation of diethyl malonate to the dibromide 21. The key-step in the synthesis of 1 consists in a twofold Curtius degradation of 22, with subsequent reduction of the carbonyl group and aromatization. The skeleton of the isomer 31 is synthesized via cycloaddition of butadiene to cyclopent-4-ene-l,3-dione (7) and addition of dichlorocarbene to the adduct 27 after ketalisation. The attempted synthesis of dihydrocycloprop[flindene (2) by base-induced elimination of several appropriately substituted precursors failed.HELVETICA CHIMICA ACTA ~-Vol. 77 (1994) Scheme I 7 8 9 4-ene-1,3-dione (7). Addition of dichlorocarbene followed by functional-group modification and aromatization of the adduct 9 as above should lead directly to 2. Resultsand Discussion. ~ Synthesis of 4,s-Dihydro-I H,3H-cycloprop[ f/inden-4-01(1) j r o m 4. The double Curtius degradation of geminal diesters, which is the key step in the proposed synthesis of 1, has been used only once in the literature [6]. Model studies were carried out in order to establish the feasibility of the approach in our system. 1,2-Bis(bromomethy1)benzene (10) was condensed with diethyl malonate [7] to afford 11, which was hydrolyzed [8] to the diacid 12 (Scheme 2). Reaction of 12 with oxalyl chloride afforded the dichloride 13, and treatment of the latter with NaN, in MeCN at 25" led to the azide 14. The azide was rearranged to the bis-isocyanate 15 by refluxing in cyclohexane. Hydrolysis of the crude 15 afforded indan-2-one (16) in 45-50% overall yield. 10 11 X = EtO 12 X = O H 13 X=C1 14 X = N , 15 X = NCO 16 X,X = 0

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“…As for the catalytic co-cyclotrimerisation of different alkynes, diynes have been frequently used as a substrate which couples with another alkyne chemo-and regioselectively (i.e. half-intermolecular [2 + 2 + 2] cycloaddition) [1, [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%