Synthesis of N,N-bis(3-butenyl)amines from 2-azaallyl dication synthetic equivalents and conversion to 2,3,6,7-tetrahydroazepines by ring-closing metathesis

N,N-Bis(3-butenyl)amines can be prepared by the double allylation of either (2-azaallyl)stannanes or (2-azaallyl)nitriles, both of which thereby act as synthetic equivalents to amine alpha,alpha'-dications (2-azaallyl dications). Allylmagnesium bromide is the reagent of choice for the double allylation of both substrates, although allyllithium also effects the double allylation of (2-azaallyl)nitriles. Ring-closing metathesis can be performed on the N-protected amines, or with in situ protonation, on the free amines to provide 2,3,6,7-tetrahydroazepines. (2-Azaallyl)nitriles can also be monoallylated to provide N-(3-butenyl)aminonitriles, whereas the double allylation of (2-azaallyl)stannanes cannot be stopped at monoallylation. (2-Azaallyl)silanes undergo monoallylation to give N-(3-butenyl)aminosilanes but do not undergo double allylation.     

A convenient and efficient route for the allylation of aromatic amines and alpha-aryl aldehydes with alkynes in the presence of a Pd(0)/PhCOOH combined catalyst system

The allylation of aromatic amines with alkynes proceeded smoothly in the presence of catalytic amounts of Pd(PPh(3))(4) and benzoic acid. The allylation products were obtained in high yields in a regio- and stereoselective manner. The effect of various groups on the nitrogen atom of anilines was studied. Regardless of the substituent (electron withdrawing or electron donating) on the aromatic ring, the reaction proceeded well. Various functionalities, including -CH(3), -OMe, -Cl, -CN, -COOMe, -NO(2) and -COCH(3) were tolerated under the reaction conditions. Similarly, the allylation of alpha-aryl aldehydes proceeded well with the same level of regio- and stereoselectivity as the allylation of aromatic amines. This reaction provides the second example of the transition metal catalyzed direct alpha-allylation of aldehydes.     

Highly efficient synthesis of homoallylic alcohols and amines via allylation of aldehydes and imines catalyzed by ZrOCl2·8H2O in water

The allylation of aldehydes and imines has efficiently been carried out by treatment with allyltributylstannane in the presence of a catalytic amount of ZrOCl₂·8H₂O in water to form the corresponding homoallylic alcohols and amines, respectively, in high yields.     

Regiodivergent Hydroaminoalkylation of Alkynes and Allenes by a Combined Rhodium and Photoredox Catalytic System

A rhodium/photoredox dual catalyzed regiodivergent α‐allylation of amines is described. As an atom‐economic and efficient method, alkynes and allenes are used as allylic electrophile surrogates in this novel protocol. With different reaction conditions, synthetically useful branched or linear homoallylic amines could be synthesized in good to excellent yields and regioselectivity. This straightforward strategy complements the traditional transition‐metal catalyzed allylation reactions.     

Why platinum catalysts involving ligands with large bite angle are so efficient in the allylation of amines: design of a highly active catalyst and comprehensive experimental and DFT study

The platinum-catalyzed allylation of amines with allyl alcohols was studied experimentally and theoretically. The complexes [Pt(eta(3)-allyl)(dppe)]OTf (2) and [Pt(eta(3)-allyl)(DPP-Xantphos)]PF(6) (5) were synthesized and structurally characterized, and their reactivity toward amines was explored. The bicyclic aminopropyl complex [Pt(CH(2)CH(2)CH(2)NHBn-kappa-C,N)(dppe)]OTf (3) was obtained from the reaction of complex 2 with an excess of benzylamine, and this complex was shown to be a deactivated form of catalyst 2. On the other hand, reaction of complex 5 with benzylamine and allyl alcohol led to formation of the 16-VE platinum(0) complex [Pt(eta(2)-C(3)H(5)OH)(DPP-Xantphos)] (7), which was structurally characterized and appears to be a catalytic intermediate. A DFT study showed that the mechanism of the platinum-catalyzed allylation of amines with allyl alcohols differs from the palladium-catalyzed process, since it involves an associative ligand-exchange step involving formation of a tetracoordinate 18-VE complex. This DFT study also revealed that ligands with large bite angles disfavor the formation of platinum hydride complexes and therefore the formation of a bicyclic aminopropyl complex, which is a thermodynamic sink. Finally, a combination of 5 and a proton source was shown to efficiently catalyze the allylation of a broad variety of amines with allyl alcohols under mild conditions.     

Synthesis and catalytic application of chiral 1,1'-Bi-2-naphthol- and biphenanthrol-based pincer complexes: selective allylation of sulfonimines with allyl stannane and allyl trifluoroborate

New easily accessible 1,1'-bi-2-naphthol- (BINOL-) and biphenanthrol-based chiral pincer complex catalysts were prepared for selective (up to 85% enantiomeric excess) allylation of sulfonimines. The chiral pincer complexes were prepared by a flexible modular approach allowing an efficient tuning of the selectivity of the catalysts. By employment of the different enantiomeric forms of the catalysts, both enantiomers of the homoallylic amines could be selectively obtained. Both allyl stannanes and allyl trifluoroborates can be employed as allyl sources in the reactions. The biphenanthrol-based complexes gave higher selectivity than the substituted BINOL-based analogues, probably because of the well-shaped chiral pocket generated by employment of the biphenanthrol complexes. The enantioselective allylation of sulfonimines presented in this study has important implications for the mechanism given for the pincer complex-catalyzed allylation reactions, confirming that this process takes place without involvement of palladium(0) species.     

Redox‐Neutral α‐Allylation of Amines by Combining Palladium Catalysis and Visible‐Light Photoredox Catalysis

An unprecedented α‐allylation of amines was achieved by combining palladium catalysis and visible‐light photoredox catalysis. In this dual catalysis process, the catalytic generation of allyl radical from the corresponding π‐allylpalladium intermediate was achieved without additional metal reducing reagents (redox‐neutral). Various allylation products of amines were obtained in high yields through radical cross‐coupling under mild reaction conditions. Moreover, the transformation was applied to the formal synthesis of 8‐oxoprotoberberine derivatives which show potential anticancer properties.     

Allylation of aldehydes and imines: promoted by reuseable polymer-supported sulfonamide of N-glycine

[reaction: see text] A allylation of aldehydes and imines (generated in situ from aldehydes and amines) with allyltributyltin promoted by recoverable and reusable the polymer-supported sulfonamide of N-glycine has been developed. Good to high yields were obtained in various cases. Most of the SnBu(3) residue can be recovered as Bu(3)SnCl. Highly stereoselective synthesis of N-Boc-(2S,3S)-3-hydroxy-2-phenylpiperidine 7 was achieved by using the P4a-mediated allylation of Boc-l-phenylglycinal as a key step.     

On the scope of diastereoselective allylation of various chiral glyoxylic oxime ethers with allyltributylstannane in the presence of a Lewis acid and triallylaluminum

The nucleophilic allylation of various chiral auxiliaries derived glyoxylic oxime ethers was studied. The use of allyltributylstannane in the presence of a Lewis acid and triallylaluminum provided the corresponding homoallylic amines in high chemical yields (up to 89%) and excellent stereoselectivities (up to >99%). The stereochemical bias of the allylation is proposed.     

An atom efficient route to N-aryl and N-alkyl pyrrolines by transition metal catalysis

The synthesis of N-aryl, N-tosyl, and N-alkyl pyrrolines from allyl alcohols and amines has been developed. The reaction sequence includes a palladium-catalyzed allylation step in which non-manipulated allyl alcohol is used to generate the diallylated amine in good to excellent yield. An excess of allyl alcohol was necessary for efficient diallylation of the amine, where the excess alcohol could be recycled three times. For aryl and tosyl amines, Pd[P(OPh)(3)](4) was used and for benzyl and alkyl amines a catalytic system comprising Pd(OAc)(2), P(n)Bu(3), and BEt(3) was used. Both the electronic properties and the steric influence of the amine affected the efficiency of the allylation. The isolated diallylated amines were transformed into their corresponding pyrrolines by ring-closing metathesis catalyzed by (H(2)IMes)(PCy(3))Cl(2)RuCHPh in good to excellent yield. A one-pot reaction was developed in which aniline was transformed into the corresponding pyrroline without isolating the diallylated intermediate. This one-pot reaction was successfully scaled-up to 1 mL of aniline in which the N-phenyl pyrroline was isolated in 95% yield. The versatility of the reaction in which 3-methyl-1-phenyl pyrroline was prepared in two-steps was demonstrated.     

Stereoselective synthesis of allylamines by iron-catalyzed cross-coupling of 3-chloroprop-2-en-1-amines with grignard reagents. Synthesis of naftifine

A general procedure for the synthesis of trans- and cis-allylamines has been developed on the basis of iron-catalyzed cross-coupling of Grignard reagents with stereochemically pure 3-chloroprop-2-en-1-amines prepared by allylation of amines with commercially available 1,3-dichloropropene isomers.     

Remarkable salt effect on In-mediated allylation of N-tert-butanesulfinyl imines in aqueous media: highly practical asymmetric synthesis of chiral homoallylic amines and isoindolinones

A highly practical and efficient asymmetric synthesis of chiral homoallylic amines by In-mediated allylation of chiral N-tert-butanesulfinyl imines in aqueous media at room temperature was developed. With 2-formylbenzoate imine substrates, the method allows the highly enantioselective achievement of a variety of pharmacologically important 3-allyl isoindolinone compounds.     

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

Main observation and conclusion [Cp*Co(CO)l2] effectively catalyzes pyridyl-directed C-H allylation of arenes with allylic amines in the presence of AgOAc and C...     

高烯丙醇和高烯丙胺的电化学合成研究进展

电化学技术已经在有机合成得到广泛重视,本文简要概述了利用羰基和亚胺的电化学烯丙基化反应合成高烯丙醇和高烯丙胺的方法. 该方法已经得到了比较瞩目的进展,特别是在水相中的电化学烯丙基化反应,充分体现了绿色化学的特点。在提高电流效率和区域选择性,利用手性催化剂进行手性合成等方面还期待更多的关注和发展.     

Diastereoselective Three Component Reaction of N‐Glyoxyloyl Camphorpyrazolidinone,Amine and Allyltributylstannane: Facile Synthesis of Homoallylic Amines

Diastereoselective allylation of imine derived from N‐glyoxyloyl camphorpyrazolidinone and amines was treated with allyltributylstannane in the presence of triflic acid. The corresponding optically enriched homoallylic amines were obtained in reasonable to high material yields and with practical levels of stereoselectivity in 10 min at ambient temperature.     

A distinct approach for the rapid synthesis of homoallylic amines starting directly from nitro compounds in water

Three-component reactions of nitroarenes, benzaldehydes, and allyltributylstannane using indium in dilute aqueous HCl at room temperature afford the corresponding homoallylic amines in high yields within 5-10 min. The conversion in one-pot synthesis involves the following steps: (i) reduction of nitro compounds to amines, (ii) formation of imines from amines and aldehydes, and (iii) allylation of imines.     

Efficient three-component one-pot benzylation and allylation of aldehydes and amines for synthesis of homobenzylamines and homoallylamines

A highly efficient, three-component one-pot benzylation and allylation of aromatic and aliphatic aldehydes and amines affords the corresponding homobenzylamines and homoallylamines in good to excellent yield. The procedure is lauded by its simplicity and manipulability.     

Enantioselective iridium-catalyzed allylic amination of ammonia and convenient ammonia surrogates

Iridium-catalyzed, asymmetric allylation of ammonia as a nucleophile occurs with stereoselectivity to form a symmetric diallylamine, and related allylation of the inexpensive ammonia equivalent potassium trifluoroacetamide or the highly reactive ammonia equivalent lithium di-tert-butyliminodicarboxylate forms a range of conveniently protected, primary, alpha-branched allylic amines in high yields, high branched-to-linear regioselectivities, and high enantiomeric excess. The reactions of ammonia equivalents were conducted with a catalyst generated from a phosphoramidite containing a single stereochemical element.     

Templates for exploratory library preparation. Derivatization of a functionalized spirocyclic 3,6-dihydro-2H-pyran formed by ring-closing metathesis reaction

The preparation of a novel spirocyclic template from tert-butoxycarbonyl-4-piperidone is reported. The synthesis of N-(tert-butoxycarbonyl)-1-oxa-9-aza-spiro[5.5]undec-3-ene (4) for exploratory library generation involves ketone allylation, etherification, and ring-closing metathesis (RCM) reactions. Epoxidation of the alkene formed in the RCM followed by addition of volatile amines to the epoxides led rapidly to an exploratory library of structurally novel spirocyclic amino alcohols. The addition of amines to epoxides derived from 4 was determined to occur primarily at C3.     

Brønsted Acid-Catalyzed General Petasis Allylation and Isoprenylation of Unactivated Ketones

Brønsted acid-catalyzed general Petasis allylation and isoprenylation of unactivated ketones were developed by using o-hydroxyaniline and the corresponding pinacolyl boronic esters. This robust methodology provided access to a broad variety of quaternary homoallylic amines and dienyl amines in high yields, proved to be applicable to a gram-scale synthesis, and allowed the synthesis of a potentially bioactive quaternary homoallylic aminodiol.