16529-68-3

Upstream product

• 623-73-4 diazoacetic acid ethyl ester 
• 498-66-8 norborn-2-ene 

Downstream Products

• 37399-09-0 exo-Tricyclo<3.2.1.0^2,4>octan-3-anti-carbonsaeure 

Relevant academic research and scientific papers

Palladium(II) carboxylates and palladium(I) carbonyl carboxylate complexes as catalysts for olefin cyclopropanation with ethyl diazoacetate

Palladium(I) carbonyl carboxylate complexes [Pd(μ-CO)(μ-RCO 2)]n (R = Me, n = 4; R = CMe3, n = 6) and the corresponding palladium(II) carboxylates (acetate and pivalate) catalyze the cyclopropanation of olefins with ethyl diazoacetate. The performance of these catalysts is similar in terms of selectivity and cyclopropane yields, regardless of the oxidation state of the metal center. However the rates of the cyclopropanation reactions are significantly higher for the acetate based catalysts than for the pivalate derivatives, which suggests that the main catalytic species are carboxylate containing palladium complexes. Kinetic measurements show that reaction rates are independent of the olefin concentration when these are 1-hexene or styrene, but norbornene exerts an inhibitory effect. In spite of this, competition experiments indicate that the cyclopropanation of styrene is 2.2 times as favorable as that of 1-hexene for any of the four catalysts. These observations indicate that while the rate-determining formation of the intermediate palladium carbenoid species is controlled by the catalyst structure, this is followed by a rapid and less specific cyclopropanation step that is not affected by the nature of the carboxylate groups present in the catalyst. An independent test using a 1:1 benzene/cyclohexane mixture of solvents showed that the transfer of ethoxycarbonylcarbene (:C(CO2Et)H) to these molecules is unselective (relative rate of benzene/cyclohexane functionalization ≈1.8, independent of the catalyst). This result can be interpreted as an indication of the involvement of free ethoxycarbonylcarbene in the carbene transfer step. The Royal Society of Chemistry 2009.

Stereoselective cyclopropanation under solvent free conditions: Catalyzed by a green and efficient recyclable Cu-exchanged bentonite

Background: The cyclopropanation reaction was inspected by addition of carbene generated from ethyl diazoacetate in the presence of a greener Cu-exchanged bentonite catalyst to olefin under solvent free condition. The cyclopropanes were obtained with good yields. Our own contribution in this area was to introduce a modified Algerian bentonite as a catalyst and microwave activation as a mode of heating. Methods: A catalytic material developed from natural type montmorillonite clays, from deposits of Maghnia (Western Algeria), by cation exchange (Cu2+) was characterized by different spectral methods. The catalytic properties of the new material were explored in cyclopropanation reaction of olefins under microwave irradiation. A comparative study with Cu-exchanged bentonite as catalyst between microwave activation and classical heating was conducted. Results: Cu2+ exchanged clay is an efficient catalyst in the generation of carbenes from diazocompounds, under microwave irradiation. The formation of carboxylate cyclopropane was performed in solvent free condition with moderate diastereoselectivity. The yields were good, and the catalyst can be reused at least three times without noticeable loss of catalytic activity. Conclusion: This work shows that the coupling "modified clay/microwave activation" is a clean and simple access to functionalized cyclopropanes. This reusable Cu exchanged clay material is shown to be as a good substitute for many sophisticated and hardly accessible catalysts.

Activation energies for the 1,2-carbon migration of ring-fused cyclopropylchlorocarbenes

Fused-ring cyclopropylchlorocarbenes 2 and 3 ring expand to fused-ring chlorocyclobutenes 10 and 11, respectively, with activation energies of 3-4 kcal/mol and activation entropies of ～-20 e.u. Carbon tunneling appears to be unimportant at low temperatures.

Platinum-catalysed cyclopropanation of olefins with ethyl diazoacetate

The addition of ethyl diazoacetate to olefins in the presence of a catalytic amount of platinum complexes provides the corresponding cyclopropanes in good to excellent yields.

ENHANCEMENT OF STEREOSELECTIVITY IN CATALYTIC CYCLOPROPANATION REACTIONS

Significat enhancement of trans(anti) stereoselectivity is achieved in rhodium(II) acetamide catalyzed cyclopropanation reactions of 2,3,4-trimethyl-3-pentyl diazoacetate (ODA) and diazoacetamides.

STERICALLY CROWDED CYCLOPROPANATION CATALYSTS. SYN-SELECTIVITY USING RHODIUM(III)PORPHYRINS

Rhodium(III)porphyrins catalyze the decomposition of ethyl diazoacetate and the transfer of ethoxycarbonylcarbene to alkenes to form cyclopropanes in moderate to high yields.When compared with other catalysts a large syn-selectivity was observed on reaction with cis-alkenes.This selectivity increased with the size of the substituents, and suggested a preferencial direction of approach of the alkene towards a rhodium-carbene complex.