ALLYLATION OF AROMATIC AMINES VIA ALLYLDIALKYLTELLURONIUM SALTS

Allyldialkyltelluronium bromides were treated with aromatic amines in 1,2-dichloroethane,readily giving allyl aryl amines in excel- lent yields.This method provides a convenient one-pot reaction for the synthesis of allylic amines.

Indium-mediated allylation of aryl trichloromethyl ketones in aqueous media

It is described that indium-mediated allylation of trichloromethyl ketones could afford the corresponding homoallylic alcohols smoothly in aqueous media.

In(OTf)_3 catalyzed allylation reaction of imines with tetraallyltin

In the presence of catalytic amount of In（OTf）3 （10 mol%）, a series of aldimines reacted with tetraallyltin in a 2：1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol （allyl）4Sn/In（OTf）3 for simple imines was developed.

Quantum chemical study on asymmetric allylation of benzaldehyde in the presence of chiral allylboronate

The quantum chemical method is employed to study the modified asymmetric allylation of benzaldehyde controlled by diisopropyl D-(-)-tartrate auxiliary. All the structures are optimized completely at the B3LYP/6-31G(d,p) level. The (R)-secondary alcohol can be achieved mainly through a six-membered ring chair-like transition state structure. From the relative reaction rates theory the main product configuration predicted is in agreement with the experiment result.

REGIOSELECTIVE ALLYLATION OF THE TERMINAL EPOXIDES BY ALLYL BROMIDE AND METALLIC ZINC OR TIN

Allylation of terminal epoxides(1)to give the homoallylic alcohols(2)and bishomoallylic alcohols(3)can be carried out successfully by allyl bromide and metallic zinc or tin.The effect of substituents on epoxides was studied.

Tin Mediated Allylation of Aldimines with Allyl Bromide

Aldimines are allylated with allyl bromide and tin powder in tetrahydrofuran to give homoallylamines in the presence of chlorotrimethylsilane.

Ru(II)-Catalyzed ortho C-H Allylation of N-Aryl-7-azaindoles with 2-Methylidene Cyclic Carbonate

A Ru(II)-catalyzed ortho allylation reaction of N-aryl-7-azaindole with readily available 2-methylidene cyclic carbonate has been developed.This reaction is an effective pathway for synthesizing 7-azaindole derivatives with a wide scope of substrates and high yields.In addition,the method can be extended to the allylation of other heterocyclic compounds and several cyclic carbonates,highlighting the practicality of this strategy for synthesis.

Asymmetric radical allylation of β-keto esters with vinyl cyclopropanes by dual photoredox/nickel catalysis

Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.

Palladium-Catalyzed Regioselective Asymmetric Chemodivergent Allylation of Oxazolones with Morita-Baylis-Hillman Adducts

Oxazolones are structural subunits in numerous natural products and designed molecules with substantial pharmacological properties.Here,a palladium-catalyzed chemodivergent regio-and enantioselective allylic alkylation of 4-or 5-substituted oxazol-2(3H)-ones with Morita-Baylis-Hillman(MBH)adducts has been developed using a spiroketal-based diphosphine as the ligand(50 examples).Interestingly,4-substituted oxazol-2(3H)-ones acted as a C-nucleophiles in the reaction to afford a range of chiral 4,5-substituted oxazol-2(3H)-ones in high yields(72-99%)with good to excellent chemo-,regio-,and enantioselectivities(C/N 95:5->99:1,b/l 91:9->99:1,85-98%ee).When a N-nucleophile was used under otherwise identical conditions,5-substituted oxazol-2(3H)-ones delivered a range of chiral 3,5-substituted oxazol-2(3H)-ones in high yields(68-98%)with good regio-and enantioselectivities(b/l 71:29-91:9,66-94%ee).The synthesis can be readily performed on gram scale under fairly low catalyst loadings,and the utility of the protocol was showcased in the facile transformation of the products into more elaborate chiral molecules.

C–H allylation of N-aryl-tetrahydroisoquinolines by merging photoredox catalysis with iodide catalysis

A dual catalytic system, combing visible light photoredox catalysis and iodide catalysis, has been developed for the functionalization of inert C–H bonds. By doing so, radical allylation reactions of N-aryl-tetrahydroisoquinolines(THIQs) were realized under extremely mild conditions, affording a wide variety of allyl-substituted THIQs in up to 78% yields.

Ligand-Controlled Palladium-Catalyzed Regiodivergent Defluorinative Allylation of gem-Difluorocyclopropanes viaσ-Bond Activation

Monofluoroalkenes are important and versatile privileged components in pharmacologically relevant molecules.Here,we report a method for the selective construction of these compounds in a diversity-oriented fashion through regiodivergent cross-coupling of gem-difluorocyclopropanes with allylboronates by employing a palladium catalyst with two different ligands,in which gem-difluorocyclopropanes were used as allyl electrophiles by C—C and C—F bond activation.In the presence of 2-biphenylyl(diphenyl)phosphine as ligand,the linear-selective allyl–allyl bond formation is highly obtained,while utilizing the sterically hindered BrettPhos(dicyclohexyl[3,6-dimethoxy-2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosphine)as the ligand favors the generation of the branched-selective product.Experimental and computational studies investigated the key steps of the cross-coupling reactions,revealing the origin of the ligand-controlled regiodivergence.

Asymmetric Catalytic α-Selective Allylation of Ketones with Allyltrifluoroborates Using Dual-Functional Chiral In^(Ⅲ)/N,N'-Dioxide Complex

Comprehensive Summary Asymmetric catalytic allylation of halo-substituted ketones and ketoesters was accomplished to yield a number of homoallylic tertiary alcohols in excellent reactivity and enantioselectivity.In the presence of chiral In^(Ⅲ)/N,N-dioxide catalyst,unusual α-selective allylation ofγ-substituted potassium allyltrifluoroborates to ketones was demonstrated.The control experiments and DFT calculation reveal that chiral In^(Ⅲ)/N,N'-dioxide catalyst plays dual-tasking roles:the formation of allylindium species via transmetalation and Lewis acid activation.Apossiblereaction pathwaywas provided tounderstandα-selectivity overy-selectivity.

Simple and Clean Synthesis: Tin-mediated Allylation of Carbonyl Compounds in Water

Tin mediated allylation of aldehydes or ketones in distilled water gives rise to the corresponding homoallyl alcohols in high yield without assistance such as heat, supersonic and acidic media.

Cobalt-Catalyzed C-H Allylation of Arenes with Allylic Amines

[Cp^(*)Co(CO)l_(2)]effectively catalyzes pyridyl-directed C-H allylation of arenes with allylic amines in the presence of AgOAc and CF_(3)COOAg.The reaction features ortho-position monoallylation of 2-pyridylarenes,giving the allylated arenes in moderate to high yields.A range of functional groups including OMe,Me,Ph,F,Cl,Br,CF_(3),C(0)Me,COOEt,and COOH groups are tolerated.Pyrim-idyl-directed C-H allylation of arenes were also performed under the same conditions.Reaction of 2-phenylpyrimidine,2-(4-methoxyphenyl)pyrimidine/and 2-(3-fluorophenyl)pyrimidine leads to a mixture of ortho-position mono-and bisallylation products.Reaction of other 2-(substituted aryl)pyrimidines resulted in ortho-position monoallylation products.

Asymmetric Synthesis of Novel Axially Chiral 2,2＇-Bipyridine N,N＇-Dioxides Bearing α-Amino Acid Residues and Their Applications in Enantioselective Allylation of Aromatic Aldehydes with Allyltrichlorosilane

A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chirality of these organocatalysts has been clearly assigned by means of CD measurements together with literature protocols. The reactivities and enantioselectivities of these organocatalysts have been examined in the reactions of aromatic aldehydes with allyltrichlorosilane, thus providing the desired products with moderate yields and enantioselectivies.

Allylation and alkylation of oxindoleketimines via imine umpolung strategy

When treated with an alkoxide base like t-BuOK in aprotic solvent,N-di phenyl methyl imino oxindoles,made conveniently through condensation of corresponding isatins with N-di phenyl methyl amine,are deprotonated to form azaallyl anions.Allylation and alkylation of this type of intermediates proceed smoothly with diverse C-electrophiles.Acidic work up finishes 3-amino-3-allyl/alkyl oxindoles.The overall transformation equals to an umpolung process at the C3 of isatins.

SnCl_2/Cu-Mediated Carbonyl Allylation Reaction in Water: Scope, Selectivity and Mechanism

Copper was found to be able to promote the SnCl2-mediated carbonyl allylation reactions in water, giving the corresponding homoallylic alcohol products in very high yields. Detailed studies showed that the reaction could be applied to a variety of carbonyl compounds including those with hydroxyl, amino and nitro groups. It was also found that this reaction showed good regioselectivities for some substrates. Furthermore, carefully controled ex-periments and in situ NMR measurements provided important insights into the mechanism of the newly developed reaction.

2-Chlorotetrafluoroethanesulfinamide Induced Diastereoselective Three-Component Aminoallylation of Aldehydes

The diastereoselective three-component reaction of aldehydes, allyl bromide, and （S）-2-chlorotetrafluoroethancsulfinamide was achieved in the presence of zinc powder and titanium（IV） isopropoxide. Compared to （S）-tert-butanesulfinamide, the reaction used zinc powder instead of indium and better results were obtained with aromatic aldehydes. Moreover, opposite stereoselectivity is observed.

Palladium-catalyzed base-and solvent-controlled chemoselective allylation of amino acids with allylic carbonates

The utilization of readily available amino acids,which is not only an oxygen nucleophile but also a nitrogen nucleophile,in palladium-catalyzed allylic substitution is realized under mild conditions.The chemoselectivity and multiple allylation are controlled by adjusting the reaction conditions.This represents the first example of this convenient access to valuable N,O-diallylated amino acids.Under the title conditions,a range of amino acids(α-,β-,γ-)and dipeptides can be readily converted in to the corresponding allylic products with excellent yields(67 examples,up to 99%yield)as well as good functional group tolerance.

Chiral Phosphoric Acid Catalyzed Enantioselective Allylation of Aldehydes with Allyltrichlorosilane

Easily accessible chiral phosphoric acid lb has been applied as efficient organocatalyst for the asymmetric al- lylation of aldehydes with allyltrichlorosilane. In the presence of 20 mol% of lb, the allylation of a broad range of aldehydes proceeded smoothly to give the corresponding homoallylic alcohol with up to 87% ee and 97% yield.