851293-03-3

Upstream product

• 132145-64-3 dimethyl 2-(p-methylphenyl)cyclopropane-1,1-dicarboxylate 
• 622-97-9 1-ethenyl-4-methylbenzene 
• 108-59-8 malonic acid dimethyl ester 
• 145838-86-4 bis(methoxycarbonyl)(phenyliodinio)methanide 

Downstream Products

• 1401466-72-5 dimethyl 2-methyl-5-(4-tolyl)-4,5-dihydropyrrole-3,3-dicarboxylate 

Relevant academic research and scientific papers

Asymmetric cyclopropanations and cycloadditions of dioxocarbenes

Methods for enantioselective transfer of carbenes starting from precursors carrying two carbonyl groups have been elaborated. A one-pot procedure for olefin cyclopropanation with CH-acidic precursors via intermediate phenyliodonium ylides has been develop

A chiral cagelike copper(I) catalyst for the highly enantioselective synthesis of 1,1-cyclopropane diesters

Triangulation method: The catalytic enantioselective cyclopropanation of multisubstituted olefins with phenyliodonium ylide malonate has been achieved in the presence of a chiral bisoxazoline copper(I) complex (see scheme). A wide range of substrates undergo the reaction to provide optically active 1,1-cyclopropane diesters in high yield with up to >99 %-ee. A rationale for the enantioselective induction has been proposed. Copyright

A chiral cagelike copper(I) catalyst for the highly enantioselective synthesis of 1,1-cyclopropane diesters

Triangulation method: The catalytic enantioselective cyclopropanation of multisubstituted olefins with phenyliodonium ylide malonate has been achieved in the presence of a chiral bisoxazoline copper(I) complex (see scheme). A wide range of substrates undergo the reaction to provide optically active 1,1-cyclopropane diesters in high yield with up to >99 %-ee. A rationale for the enantioselective induction has been proposed. Copyright

First X-ray structure of a N-naphthaloyl-tethered chiral dirhodium(II) complex: Structural basis for tether substitution improving asymmetric control in olefin cyclopropanation

Good-ee! The first one-pot olefin cyclopropanation that gives high ee is reported. The optimized catalyst is the 4-Br-substituted chiral paddle-wheel tetracarboxylatodirhodium(II) complex based on N-naphthaloyl-(S)-tert-leucinate. X-ray structural analysis of the parent catalyst reveals a square chiral crown cavity shrouding the axial coordination site (see figure) Figure Presentation

Rhodium(II)-catalyzed inter- and intramolecular cyclopropanations with diazo compounds and phenyliodonium ylides: Synthesis and chiral analysis

Different classes of cyclopropanes derived from Meldrum's acid (=2,2-dimethyl-1,3-dioxane-4,6-dione; 4), dimethyl malonate (5), 2-diazo-3-(silyloxy)but-3-enoate 16, 2-diazo-3,3,3-trifluoropropanoate 18, diazo(triethylsilyl)acetate 24a, and diazo(dimethylphenylsilyl)acetate 24b were prepared via dirhodium(II)-catalyzed intermolecular cyclopropanation of a set of olefins 3 (Schemes 1 and 4-6). The reactions proceeded with either diazo-free phenyliodonium ylides or diazo compounds affording the desired cyclopropane derivatives in either racemic or enantiomer-enriched forms. The intramolecular cyclopropanation, of allyl diazo(triethylsilyl)acetates 28, 30, and 33 were carried out in the presence of the chiral dirhodium(II) catalyst [Rh 2{(S)-nttl)4}] (9) in toluene to afford the corresponding cyclopropane derivatives 29, 31 and 34 with up to 37% ee (Scheme 7). An efficient enantioselective chiral separation method based on enantioselective GC and HPLC was developed. The method provides information about the chemical yields of the cyclopropane derivatives, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intramolecular cyclopropanation reactions and avoids time-consuming workup procedures.

Rh(II)-catalyzed enantioselective cyclopropanation of olefins with dimethyl malonate via in situ generated phenyliodonium ylide

(Chemical Equation Presented) Olefins are cyclopropanated with dimethyl malonate (1a) iodosylbenzene (Phl=O) and a Rh(II) carboxylate catalyst via an in situ generated phenyliodonium ylide (1c). Enantioselectivities of up to 90% for 4-bromostyrene and 98% for pent-1-ene have been observed with (S)-N-4-bromo-1,8-naphthanoyl-tert-leucine (4c) as the chiral ligand. The same catalyst was effective for olefin cyclopropanation with Meldrum's acid, giving cyclopropanes with 96% (with styrene) and 87% ee (with pent-1-ene), respectively.