1093350-41-4

Upstream product

• 6773-29-1 dimethyl diazomalonate 
• 768-56-9 4-Phenylbut-1-ene 
• 108-59-8 malonic acid dimethyl ester 
• 100-42-5 styrene 
• 75073-98-2 dimethyl (E)-2-styrylcyclopropane-1,1-dicarboxylate 
• 145838-86-4 bis(methoxycarbonyl)(phenyliodinio)methanide 

Relevant academic research and scientific papers

Advancing the reactivity of dimethylcyclopropane-1,1-dicarboxylates via cross metathesis

Cross metathesis of the readily available dimethyl 2-vinylcycloropane-1,1- dicarboxylate with a variety of olefins gave divergent access to new donor-acceptor cyclopropanes bearing a π-donor alkenyl substituent. The synthetic utility of these cyclopropanes was shown by their participation in cycloaddition reactions with nitrones to yield the anticipated tetrahydro-1,2-oxazines. Hydrogenation yielded the alkyl-substituted adducts which would be more difficult to access via other means. Georg Thieme Verlag Stuttgart New York.

Formal homo-nazarov and other cyclization reactions of activated cyclopropanes

The Nazarov cyclization of divinyl ketones gives access to cyclopentenones. Replacing one of the vinyl groups by a cyclopropane leads to a formal homo-Nazarov process for the synthesis of cyclohexenones. In contrast to the Nazarov reaction, the cyclization of vinyl-cyclopropyl ketones is a stepwise process, often requiring harsh conditions. Herein, we describe two different approaches for further polarization of the three-membered ring of vinyl-cyclopropyl ketones to allow the formal homo-Nazarov reaction under mild catalytic conditions. In the first approach, the introduction of an ester group α to the carbonyl on the cyclopropane gave a more than tenfold increase in reaction rate, allowing us to extend the scope of the reaction to non-electron-rich aryl donor substituents in the β position to the carbonyl on the cyclopropane. In this case, a proof of principle for asymmetric induction could be achieved using chiral Lewis acid catalysts. In the second approach, heteroatoms, especially nitrogen, were introduced β to the carbonyl on the cyclopropane. In this case, the reaction was especially successful when the vinyl group was replaced by an indole heterocycle. With a free indole, the formal homo-Nazarov cyclization on the C3 position of indole was observed using a copper catalyst. In contrast, a new cyclization reaction on the N1 position was observed with BrAnsted acid catalysts. Both reactions were applied to the synthesis of natural alkaloids. Preliminary investigations on the rationalization of the observed regioselectivity are also reported.

General method for the synthesis of phenyliodonium ylides from malonate esters: Easy access to 1,1-cyclopropane diesters

(Chemical Equation Presented) A general method to access phenyliodonium ylides from malonates has been developed. These ylides provide easy access to a variety of useful 1,1-cyclopropane diesters using rhodium or copper catalysis. Moreover, the iodonium ylide of dimethyl malonate was obtained in 78% yield using improved conditions that involve a simple filtration step to isolate the desired product. This ylide was shown to be a safer and convenient alternative to the corresponding diazo compound and a very efficient way to 1,1-cyclopropane diesters when used with a catalytic amount of Rh2(esp)2.

Rhodium-catalyzed cyclopropanation of alkenes with dimethyl diazomalonate

The outstanding ability of dirhodium α,α,α′, α′-tetramethyl-1,3-benzenedipropanoate [Rh2(esp) 2; esp=α,α,α′,α′-tetramethyl-1,3- benzene-dipropanoate] to catalyze the cyclopropanation of a wide range of alkenes with malonate-derived carbenoids under mild reaction conditions is reported in this communication. The experimental protocol is remarkably simple, uses readily accessible and stable dimethyl diazomalonate with very low catalyst loading. More importantly, the alkene is employed as a limiting reagent.