29816-85-1

Upstream product

• 106-96-7 propargyl bromide 
• 28987-79-3 m-tolylmagnesium bromide 
• 620-23-5 m-tolyl aldehyde 
• 100-80-1 3-methylstyrene 
• 127510-51-4 1-(2,2-dibromocyclopropyl)-3-methylbenzene 
• 625-95-6 3-Iodotoluene 
• 53915-69-8 allenyltributylstannane 

Downstream Products

• 502431-16-5 CH₃C₆H₄CHC(Si(CH₃)3)(CH₂Sn(C₄H₉)3) 
• 1402235-30-6 2-(3-(3-methylphenyl)prop-1-en-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 
• 1402235-26-0 (Z)-2-(1-(3-methylphenyl)prop-1-en-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 
• 1644189-04-7 N¹,N¹,N³,N³-tetrabenzyl-2-(3-methylbenzylidene)propane-1,3-diamine 
• 62164-86-7 4-(m-tolyl)but-3-enoic acid 

Relevant academic research and scientific papers

Photoredox Catalyzed Sulfonylation of Multisubstituted Allenes with Ru(bpy)3Cl2 or Rhodamine B

A highly regio- and stereoselective sulfonylation of allenes was developed that provided direct access to α, β-substituted unsaturated sulfone. By means of visible-light photoredox catalysis, the free radicals produced by p-toluenesulfonic acid reacted with multisubstituted allenes to obtain Markovnikov-type vinyl sulfones with Ru(bpy)3Cl2 or Rhodamine B as photocatalyst. The yield of this reaction could reach up to 91%. A series of unsaturated sulfones would be used for further transformation to some valuable compounds.

Polymerization of Allenes by Using an Iron(II) β-Diketiminate Pre-Catalyst to Generate High Mn Polymers

Herein, we report an iron(II)-catalyzed polymerization of arylallenes. This reaction proceeds rapidly at room temperature in the presence of a hydride co-catalyst to generate polymers of weight up to Mn=189 000 Da. We have determined the polymer structure and chain length for a range of monomers through a combination of NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. Mechanistically, we postulate that the co-catalyst does not react to form an iron(II) hydride in situ, but instead the chain growth is proceeding via a reactive Fe(III) species. We have also performed kinetic and isotopic experiments to further our understanding. The formation of a highly unusual 1,3-substituted cyclobutane side-product is also investigated.

Intermolecular Allene Functionalization by Silver-Nitrene Catalysis

Under silver catalysis conditions, using [Tp*,BrAg]2 as the catalyst precursor, allenes react with PhI═NTs in the first example of efficient metal-mediated intermolecular nitrene transfer to such substrates. The nature of the substituent at the allene seems crucial for the reaction outcome since arylallenes are converted into azetidine derivatives, whereas methylene aziridines are the products resulting from alkylallenes. Mechanistic studies allow proposing that azetidines are formed through unstable cyclopropylimine intermediates, which further incorporate a second nitrene group, both processes being silver-mediated. Methylene aziridines from alkylallenes derive from catalytic nitrene addition to the allene double bonds. Both routes have resulted to be productive for further synthetic transformations affording aminocyclopropanes.

Trifluoromethylation of Allenes: An Expedient Access to α-Trifluoromethylated Enones at Room Temperature

A silver(I) catalyzed regioselective trifluoromethylation of allenes using Langlois's salt (NaOSOCF3) is demonstrated. This transformation enables direct expedient access to α-trifluoromethylated acroleins, which are valuable synthons for a number of pharmaceuticals and agrochemicals containing vinyl-CF3 moieties. Versatility of this trifluoromethylation method has been established with good yield and excellent regioselectivity. Preliminary experiments and computational studies were carried out to elucidate the mechanistic insight of this protocol.

Enantioselective Copper-Catalyzed Three-Component Carboboronation of Allenes: Access to Functionalized Dibenzo [b,f][1,4]oxazepine Derivatives

A copper-catalyzed enantioselective three-component difunctionalization of allenes with seven-membered cyclic imines and bis(pinacolato)diboron (B2(Pin)2) to approach functionalized dibenzo[b,f][1,4]oxazepine derivatives is developed. The chiral products are obtained in up to 81% yield, >20:1 dr, and 98% ee when either a chiral diphosphine ligand or a chiral ferrocenyl-based P,N-ligand is used. Furthermore, the reaction exhibits reversed diastereoselectivities when the chiral diphosphine ligand and the chiral P,N-ligand are used respectively. (Figure presented.).

Palladium-Catalyzed Oxidative Carbonylative Coupling of Arylallenes, Arylboronic Acids, and Nitroarenes

In this Letter, a palladium-catalyzed multicomponent procedure for the selective synthesis of α-substituted α,β-unsaturated ketones has been developed. With readily available allenes, arylboronic acids, and nitroarenes as the substrates, the reaction proceeds selectively to the desired α-substituted enones. Notably, no manipulation of carbon monoxide gas is needed here, and Mo(CO)6 has been applied as a stable solid CO source instead. Additionally, as an oxidative coupling reaction, nitroarenes are used as both the amine source and the oxidant to regenerate the active palladium species.

Fluorinative Rearrangements of Substituted Phenylallenes Mediated by (Difluoroiodo)toluene: Synthesis of α-(Difluoromethyl)styrenes

Phenylallenes undergo fluorinative rearrangement upon the action of (difluoroiodo)toluene in the presence of 20 mol % BF3?OEt2 to yield α-difluoromethyl styrenes. This unprecedented reaction was entirely chemoselective for the internal allene π bond, and showed remarkable regioselectivity during the fluorination event. Substituted phenylallenes, phenylallenes possessing both phenyl- and α-allenyl substituents, and diphenylallenes were investigated, and good functional-group compatibility was observed throughout. The ease with which allenes can be prepared on a large scale, and the operational simplicity of this reaction allowed us to rapidly access fluorine-containing building blocks that have not been accessed by conventional deoxyfluorination strategies.

Highly Regio- and Enantioselective Alkoxycarbonylative Amination of Terminal Allenes Catalyzed by a Spiroketal-Based Diphosphine/Pd(II) Complex

An enantioselective alkoxycarbonylation-amination cascade process of terminal allenes with CO, methanol, and arylamines has been developed. It proceeds under mild conditions (room temperature, ambient pressure CO) via oxidative Pd(II) catalysis using an aromatic spiroketal-based diphosphine (SKP) as a chiral ligand and a Cu(II) salt as an oxidant and affords a wide range of α-methylene-β-arylamino acid esters (36 examples) in good yields with excellent enantioselectivity (up to 96% ee) and high regioselectivity (branched/linear > 92:8). Preliminary mechanistic studies suggested that the reaction is likely to proceed through alkoxycarbonylpalladation of the allene followed by an amination process. The synthetic utility of the protocol is showcased in the asymmetric construction of a cycloheptene-fused chiral β-lactam.

Palladium-catalyzed insertion of an allene into an aminal: Aminomethylamination of allenes by C-N bond activation

A new and atom-economic palladium-catalyzed aminomethylamination of allenes with aminals by C-N bond activation is described. This direct and operationally simple method provides a fundamentally novel approach for the synthesis of 1,3-diamines. Mechanistic studies suggest that a unique cationic π-allylpalladium complex containing an aminomethyl moiety is generated as a key intermediate through the carbopalladation of the allene with a cyclometalated palladium-alkyl species.

Synthesis of allenes via Nickel-catalyzed cross-coupling reaction of propargylic bromides with grignard reagents

We describe a convenient method for the synthesis of terminal allenes from cross-coupling of propargylic bromide with Grignard reagent. The reaction of propargylic bromide with 1.2 equivalents of Grignard reagent mediated by Ni(acac)2 (2 mol%) and Ph3P (4 mol%) in THF may produce terminal allenes in good yields and high regioselectivities at room temperature. Georg Thieme Verlag Stuttgart · New York.