Platinum-catalyzed allylation of aminonaphthalenes with allylic acetates

The activation of C-O bonds in allylic acetates has been accelerated by carrying out the reactions in the presence of platinum complexes associated with ligands. Platinum-catalyzed allylation of aminonaphthalenes with allylic acetates leads to N-allylic aminonaphthalenes in good yields.     

Palladium-catalyzed and samarium-promoted coupling of stereochemically-biased allylic acetates with carbonyl compounds

Stereochemically-biased bicyclic allylic acetates endo- and exo-1 were shown as being allyl donors for Pd-catalyzed carbonyl allylation using stoichiometric quantities of samarium diodide. Cyclopentenyl acetate and bicyclic derivatives 1 react with cyclic ketones in the presence of SmI₂ without requirement of palladium catalysis. Use of enantiomerically enriched substrate suggests that the reaction goes through a π-allyl samarium complex. However, this reactivity appears to be restricted to strained cyclopentenyl acetates since other linear and cyclic allylic acetates do not give the carbonyl allylation product.     

Ruthenium complex catalyzed allylation of aldehydes with allylic acetates

Ruthenium complexes such as Ru₃(CO)₁₂ and RuCl₃·nH₂O show high catalytic activity in the allylation of aldehydes by allylic acetates at 120°C to give homoallylic alcohols in good yields.     

Platinum-catalyzed allylation of aminonaphthalenes with allylic acetates in water

The activation of C-O bonds in allylic acetates in water as a suspension medium has been accelerated by carrying out the reactions in the presence of platinum complexes associated with ligands. The platinum-catalyzed allylation of aminonaphthalenes using allylic acetates gave the corresponding N-allylic aminonaphthalenes in good yields.     

Reductive coupling of allylic acetates with carbonyl compounds by using Pd(0)-SmI2 system

Reductive coupling of allylic acetates with carbonyl compounds proceeded by SmI₂ in the presence of catalytic Pd(0) to yield homoallylic alcohols.     

Iodine-catalyzed allylation and propargylation of indoles with allylic and propargylic acetates

A mild and efficient allylation/propargylation of indoles has been developed with high regioselectivity and excellent yields. In the presence of catalytic molecular iodine, various indoles could react with allylic/propargylic acetates smoothly at room temperature to exclusively provide C-3 alkylated products.     

Iron-catalyzed allylation of ketones

Allylation of ketones has been efficiently performed using iron-complex catalysis and led to homoallylic alcohols in high yields.     

First example of molecular iodine-catalyzed allylation and alkynylation of cyclic allylic acetates

Cyclic allylic acetates undergo smooth allylation and alkynylation with allyltrimethylsilane and alkynyl silanes in the presence of molecular iodine under mild conditions to afford the corresponding allylated and alkynylated cyclohexene derivatives in good yields with high selectivity.     

Indium-mediated allylation of carbonyl compounds with an allylic bromide in aqueous media: anomalous syn-diastereoselectivity regardless of allylic bromide geometry

Anomalous syn-diastereoselectivity of indium-mediated coupling of aldehydes with bromides Z-3b and E-3b is reported. The reaction afforded high syn selectivity regardless of the allylic bromide geometry. Preliminary studies on the enantioselective indium-mediated allylation were attempted and found to give the desired products in moderate yield with high syn selectivity and enantioselectivity.     

Mesoporous aluminosilicate-catalyzed allylation of carbonyl compounds and acetals

A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both carbonyl compounds and acetals with allylsilanes to afford the corresponding homoallyl silyl ethers and homoallyl alkyl ethers, respectively. Both the mesoporous structure and the presence of aluminum moiety were indispensable for the high catalytic activity of Al-MCM-41. Moreover, Al-MCM-41 could catalyze the reaction of acetals chemoselectively in the presence of the corresponding carbonyl compounds. The solid acid catalyst Al-MCM-41 could be recovered easily by filtration and could be reused three times without a significant loss of catalytic activity.     

Selective allylation of carbonyl compounds in aqueous media

The use of aqueous neutral media leads to excellent yields of homoallylic alcohols from reaction sof allyl halides with carbonyl compounds in the presence of tin or zinc. The stereochemical course and range of application of this reaction have been investigated.     

Iron-catalyzed intramolecular allylic C-H amination

A highly selective C-H amination reaction under iron catalysis has been developed. This novel system, which employs an inexpensive, nontoxic [Fe(III)Pc] catalyst (typically used as an industrial ink additive), displays a strong preference for allylic C-H amination over aziridination and all other C-H bond types (i.e., allylic > benzylic > ethereal > 3° > 2° ? 1°). Moreover, in polyolefinic substrates, the site selectivity can be controlled by the electronic and steric character of the allylic C-H bond. Although this reaction is shown to proceed via a stepwise mechanism, the stereoretentive nature of C-H amination for 3° aliphatic C-H bonds suggests a very rapid radical rebound step.     

Homogeneously catalysed isomerisation of allylic alcohols to carbonyl compounds

Isomerisation of allylic alcohols forms an elegant shortcut to carbonyl compounds in a completely atom-economical process that offers several useful applications in natural-product synthesis and in bulk chemical processes. This review focuses on the heart of isomerisation catalysis: the catalyst. Combinations of transition metals (from Group 4 to 10), ligands and reaction conditions are compared with respect to yield, turnovers, rate and selectivity. A selected number of clever solutions to synthetic problems are highlighted, such as the synthesis of enols and enolates, chiral carbonyl compounds and silyl substituted ketones. Furthermore, a general overview of the mechanisms proposed for the isomerisation of allylic alcohols is given while some catalyst systems are singled out to discuss mechanistic research.     

Indium-catalyzed allylation of carbonyl compounds with the Mn/TMSCl system

Allylation of aldehydes and ketones with allyl bromide was performed with a catalytic amount of indium powder (from 0.01 to 0.1 equiv.) in THF in the presence of manganese and trimethylsilyl chloride as the reducing and oxophilic agent, respectively.     

Iodine-catalyzed allylation of 1,3-dicarbonyl compounds with allylic alcohols at room temperature

A highly efficient iodine-catalyzed allylation of 1,3-dicarbonyl compounds with a wide variety of allylic alcohols has been developed. The reaction is operationally straightforward and proceeds under very mild conditions at room temperature in good to excellent yields (up to 99%) and regioselectivity.     

Grignard-type allylation of carbonyl compounds in methanol by the electrochemically recycled allyltin reagent.

An electrochemical allylation of aldehydes and ketones in methanol was achieved by the electroreductive regeneration of diallyltin reagent in the presence of a catalytic amount of tin, affording the corresponding homoallyl alcohols in 72 – 91% yields.     

醋酸烯丙酯选择性地合成烯丙基硒醚

醋酸烯丙酯被Pd(PPh3)4-SmI2还原，并发生中间体π-烯丙基钯络合物的极性 反转，而后与芳基硒溴化物作用，生成烯丙基硒醚．     

Gallium metal mediated allylation of carbonyl compounds and imines under solvent-free conditions

Gallium metal is effective in mediating the allylation of various carbonyl compounds and imines under solvent-free conditions, with the application of sonic energy, affording the corresponding homoallylic alcohols and amines. The imines themselves were also prepared under solventless conditions in high yield, thereby establishing a two-step solvent-free synthesis of homoallylic amines. In comparison, indium metal produced a mixture of the desired homoallylic secondary amine and the bis-allylated species via an iminium ion intermediate.     

Samarium-promoted coupling of pyridine-based heteroaryl analogues of benzylic acetates with carbonyl compounds

2-Substituted pyridine, quinoline, isoquinoline, bipyridine, and 1,10-phenanthroline analogues of benzylic acetates undergo SmI(2)-promoted coupling with aldehydes and ketones to afford (2-hydroxyalkyl)heteroaromatics. [reaction: see text]