196614-97-8

Upstream product

• 908094-04-2 phenyldiazomethane 
• 614-47-1 1,3-diphenyl-propen-3-one 
• 100-39-0 benzyl bromide 
• 3471-08-7 (2SR,3SR)-2,3-diphenylcyclopropanecarboxylic acid 

Downstream Products

• 17608-67-2 cis-2,3-diphenyl-1-benzoylcyclopropane 

Relevant academic research and scientific papers

Catalytic cyclopropanation of electron deficient alkenes mediated by chiral and achiral sulfides: Scope and limitations in reactions involving phenyldiazomethane and ethyl diazoacetate

Phenyldiazomethane reacts with electron deficient alkenes in the presence of catalytic amounts of transition metal catalyst [Rh2(OAc)4 was better than Cu(acac)2] and catalytic amounts of sulfide to give cyclopropanes. Pentamethylene sulfide was found to be superior to tetrahydrothiophene and the optimum solvent was toluene. Under these optimised conditions a range of enones were cyclopropanated in high yields. Cyclic enones and acrylates were not successful in this process. The use of the chiral 1,3-oxathiane derived from camphorsulfonyl chloride in 2 steps in this process furnished cyclopropanes in good yield and very high enantiomeric excess (>97% ee). The absolute stereochemistry of cyclopropane 10 was proven by X-ray analysis and the origin of the stereochemical induction has been rationalised. Extension of this work to include diazoesters was partially successful. Again pentamethylene sulfide was found to be superior to tetrahydrothiophene, but this time both Rh2(OAc)4 and Cu(acac)2 were found to be equally effective. Enones, fumarates and unsaturated nitro compounds worked well but simple acrylates and unsaturated aldehydes were not effective substrates. Control experiments were conducted in which the stabilised ylide was isolated and reacted with the less successful substrates and, whilst unsaturated aldehydes still gave low yields, simple acrylates gave high yields of the corresponding cyclopropane. The use of the chiral 1,3-oxathiane was not successful with these more stable diazo compounds.

Organoselenium-Catalyzed Asymmetric Cyclopropanations of (E)-Chalcones

We report a new class of chiral tetrahydroselenophene based on (S)-diphenyl(tetrahydroselenophen-2-yl)methanol, which was prepared from (R)-3-(3-bromopropyl)-2,2-diphenyloxirane and sodium selenide. These chiral tetrahydroselenophene-based compounds were used to catalyze asymmetric cyclopropanation reactions; the selenonium ylide intermediates formed from these selenium-containing catalysts and benzyl bromide efficiently react with (E)-chalcones to give various cyclopropanes (27 examples) with excellent enantioselectivities of ≤99% ee and are the first examples of organoselenium-catalyzed asymmetric cyclopropanations.

Enhanced diastereoselectivity via confinement: Diastereoselective photoisomerization of 2,3-diphenyl-1-benzoylcyclopropane derivatives within zeolites

Photochemistry of optically pure trans-2,3-diphenyl-1-benzoylcyclopropane has been examined in isotropic solution and within zeolites. Results suggest that it isomerizes by cleavage of either the C1-C2 or C1-C3

Catalytic asymmetric cyclopropanation of electron deficient alkenes mediated by chiral sulfides

Catalytic asymmetric cylopropanation of enones has been achieved using diazo compounds, catalytic quantities of a metal catalyst and a camphor-derived thioacetal; this sulfide shows exceptionally high levels of enantioselectivity.

A NOVEL CATALYTIC CYCLE FOR THE SYNTHESIS OF EPOXIDES USING SULFUR YLIDES, AND APPLICATION TO THE SYNTHESIS OF CYCLOPROPANES AND AZIRIDINES.

We have developed a new catalytic cycle for the synthesis of epoxides from carbonyl compounds and diazocompounds.These reactions are mediated by catalytic quantities of rhodium acetate (0.01 eq.) and dimethyl sulfide (0.2 eq.).In this catalytic cycle, phenyl diazomethane is decomposed by rhodium acetate to give a metallocarbene and this reacts with the sulfide to give a sulfur ylide which in turn reacts with the aldehyde to give an epoxide and returns the sulfide back into the catalytic cycle.The use of catalytic amounts of chiral sulfides gives non-racemic epoxides.It has been found that other diazocompounds can be used in the catalytic cycle e.g.N,N-diethyl diazoacetamide.In addition, it has been found that substitution of aldehydes for enones furnishes cyclopropanes, and substitution with imines gives aziridines.For the preparation of terminal epoxides, diazomethane could not be used instead of phenyl diazomethane.Instead, it was discovered that terminal epoxides could be prepared using diethyl zinc, chloroiodomethane, dimethyl sulfide and an aldehyde.A second catalytic cycle for epoxidation has therefore been developed.Key Words catalytic, asymmetric synthesis, sulfur ylide, epoxide, aziridine, cyclopropane, rhodium acetate, Simmons Smith.