N-tosyl Aldimines Research Articles

Active bismuth mediated allylation of carbonyls/N-tosyl aldimines and propargylation of aldehydes in water

Active bismuth is synthesized by the chemical reduction of bismuth trichloride using freshly prepared sodium stannite solution as the reducing agent at room temperature. The as-synthesized active bismuth is applied as a reagent for the synthesis of homoallyl alcohol/homopropargyl alcohol from allyl bromide/propargyl bromide and carbonyl compounds in water at $$50\,{^{\circ }}\hbox {C}$$ . The homoallyl amines are also synthesized from N-tosyl aldimines and allyl bromide using active bismuth reagent in good yields. No assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere is required for this reaction. The waste bismuth material obtained after the completion of the organic reaction can be reduced to active bismuth by sodium stannite solution and successfully reused for mediating the allylation of aldehydes. Synopsis Active bismuth mediated allylation/crotylation of aldehydes is developed in water to get homoallyl alcohols. The method is also applied for the allylation of N-tosyl aldimines and propargylation of aldehydes in water to achieve the homoallyl amines and homopropargyl alcohols, respectively. The reactions do not require the assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere.

Microwave assisted synthesis of dihydropyrrole by AgOAc catalyzed intramolecular cyclization reaction of homopropargyl amine

A series of 5-aryl dihydropyrrole was synthesized from the intramolecular cyclization reaction of homopropargyl amine in the presence of AgOAc as catalyst under microwave irradiation reaction conditions. The homopropargyl amine was prepared by the reaction of propargyl bromide with N-tosyl aldimine under a sonochemical Barbier-type reaction condition. Further aromatization reaction of 5-aryl dihydropyrrole in KOtBu/DMSO can afford 2-aryl pyrrole under microwave irradiation reaction conditions.

Recyclable chiral dinuclear copper(II) complexes catalyzed asymmetric Friedel–Crafts alkylation of 1-naphthol using N-tosyl aldimine

A highly efficient dinuclear copper complex catalyzed Friedel–Crafts reaction has been demonstrated for the alkylation of 1-naphthol using N-tosyl aldimine. In this context, various chiral amino alcohol derived Schiff base ligands with different achiral and chiral linkers were synthesized and their copper (II) complexes were generated in situ. One of the dinuclear copper complexes with chiral linker has emerged as an efficient catalyst and affords the desired arene products in excellent enantioselectivities (ee up to 99%) with very good yields (up to 98%). The dinuclear catalyst used in this study was recoverable and recyclable with retention of its catalytic activity.

InBr3 catalyzed tandem construction of C–C, C–O and C–N bonds: a concise, convenient and atom-economical strategy for the synthesis of spiro oxazolidine oxindole derivatives

A versatile, operationally simple and highly efficient one-pot three-component approach for the synthesis of spiro oxazolidine oxindole derivatives has been developed by the domino reaction of isatins, arylacetylenes, and N-tosyl aldimines in acetonitrile catalyzed by InBr3 at ambient temperature. The significant advantages of this protocol are highlighted by excellent yields, cleaner reaction profiles, avoidance of toxic catalyst, broader substrate scope, and successful assembly of three new C–C, C–N and C–O bonds.

Synthesis of α,β-diamino acid derivatives via asymmetric Mannich reactions of glycine imino esters catalyzed by a chiral phosphoramidite·silver complex

AgOTf·phosphoramidite complexes efficiently catalyze the enantioselective Mannich-type reaction between benzophenone-imine glycine methyl ester and N-tosyl aldimines in the absence of a base. The corresponding syn-adducts, which are the direct precursors of α,β-diamino acids, are obtained with moderate to good syn-diastereoselectivities (up to 9:1) and high enantioselectivities (up to 99% ee).

ChemInform Abstract: Chemoselective Synthesis of β‐Amino Ester or β‐Lactam via Sonochemical Reformatsky Reaction.

A series of β-amino esters were synthesized by the reaction of N-tosyl aldimine or N-hydroxy aldimine with bromoacetate by sonochemical Reformatsky reaction. The β-N-hydroxyamino ester was obtained and the formed sensitive hydroxylamino functionality was resistant under the reaction condition. The β-lactam also was synthesized by the reaction of N-p-methoxy aldimine as reacting substrate under this sonochemical Reformatsky reaction condition.

ChemInform Abstract: One‐Pot Formation of Fluorescent γ‐Lactams Having an α‐Phosphorus Ylide Moiety Through Three‐Component α(δ′)‐Michael Reactions of Phosphines with an Enyne and N‐Tosyl Aldimines.

ChemInformVolume 45, Issue 25 Organoelement Compounds ChemInform Abstract: One-Pot Formation of Fluorescent γ-Lactams Having an α-Phosphorus Ylide Moiety Through Three-Component α(δ′)-Michael Reactions of Phosphines with an Enyne and N-Tosyl Aldimines. Yu-Wei Lin, Yu-Wei Lin Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this authorJie-Cheng Deng, Jie-Cheng Deng Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this authorYou-Zung Hsieh, You-Zung Hsieh Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this authorShih-Ching Chuang, Shih-Ching Chuang Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this author Yu-Wei Lin, Yu-Wei Lin Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this authorJie-Cheng Deng, Jie-Cheng Deng Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this authorYou-Zung Hsieh, You-Zung Hsieh Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this authorShih-Ching Chuang, Shih-Ching Chuang Dep. Appl. Chem., Natl. Chiao Tung Univ., Hsinchu 30010, TaiwanSearch for more papers by this author First published: 05 June 2014 https://doi.org/10.1002/chin.201425199Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume45, Issue25June 24, 2014 RelatedInformation

Isothiourea-Mediated Asymmetric Functionalization of 3-Alkenoic Acids

Isothiourea HBTM-2.1 promotes the catalytic asymmetric α-functionalization of 3-alkenoic acids through formal [2 + 2] cycloadditions with N-tosyl aldimines and formal [4 + 2] cycloadditions with either 4-aryltrifluoromethyl enones or N-aryl-N-aroyl diazenes, providing useful synthetic building blocks in good yield and with excellent enantiocontrol (up to >99% ee). Stereodefined products are amenable to further synthetic elaboration through manipulation of the olefinic functionality.

ChemInform Abstract: Cobalt‐Catalyzed Oxidative [3 + 2] Cycloaddition Reactions: An Efficient Synthesis of Pyrrolo‐ and Imidazo‐[2,1‐a]isoquinolines.

AbstractThe cobalt‐catalyzed reaction of tetrahydroquinoline (I) with in situ generated aldimines leads to 5,6‐dihydroimidazo[2,1‐a]isoquinolines (III), whilst the reaction of tetrahydroquinolines (IV) with N‐tosyl aldimines as dipolarophiles affords a variety of hexahydroimidazo[2,1‐a]isoquinolines (VI).

One-pot formation of fluorescent γ-lactams having an α-phosphorus ylide moiety through three-component α(δ′)-Michael reactions of phosphines with an enyne and N-tosyl aldimines

We demonstrate a straightforward synthesis of γ-lactams possessing an α-phosphorus ylide moiety from assembly of phosphines, N-tosyl aldimines and an enyne through an initial α(δ')-attack of phosphines to an enyne in up to 79% yield. The investigated multicomponent reaction tolerates a variety of triarylphosphines and electron-poor aldimines to give γ-lactams in one pot. One of the lactams, with the tri(p-tol)phosphine and 4-cyanophenyl moiety, exhibits fluorescence emission at 447 nm with a quantum yield of 0.11.

Chemoselective Synthesis of β‐Amino Ester or β‐Lactam via Sonochemical Reformatsky Reaction

AbstractA series of β‐amino esters were synthesized by the reaction of N‐tosyl aldimine or N‐hydroxy aldimine with bromoacetate by sonochemical Reformatsky reaction. The β‐N‐hydroxyamino ester was obtained and the formed sensitive hydroxylamino functionality was resistant under the reaction condition. The β‐lactam also was synthesized by the reaction of N‐p‐methoxy aldimine as reacting substrate under this sonochemical Reformatsky reaction condition.

Catalytic Asymmetric Diaziridination

Key words chiral diaziridines - phase-transfer catalysis - cinchonine-derived catalysts - N-tosyl aldimines

Catalytic Asymmetric Diaziridination

The first catalytic enantio- and diastereoselective synthesis of diaziridines is presented. Aziridination of N-tosyl aldimines applying modified hydroxylamine under asymmetric phase-transfer catalysis furnished optically active diaziridines. The diaziridines are formed as a single diastereomer in up to 96% ee, containing two orthogonal N-protecting groups, which can be deprotected selectively.

Enantioselective Construction of Pyrrolidines by Palladium-Catalyzed Asymmetric [3 + 2] Cycloaddition of Trimethylenemethane with Imines

A protocol for the enantioselective [3 + 2] cycloaddition of trimethylenemethane (TMM) with imines has been developed. Central to this effort were the novel phosphoramidite ligands developed in our laboratories. The conditions developed to effect an asymmetric TMM reaction using 2-trimethylsilylmethyl allyl acetate were shown to be tolerant of a wide variety of imine acceptors to provide the corresponding pyrrolidine cycloadducts with excellent yields and selectivities. Use of a bis-2-naphthyl phosphoramidite allowed the successful cycloaddition of the parent TMM with N-Boc imines, and has further permitted the reaction of substituted donors with N-tosyl aldimines and ketimines in high regio-, diastereo-, and enantioselectivity. Use of a diphenylazetidine ligand allows the complementary synthesis of the exocyclic nitrile product shown, and we demonstrate control of the regioselectivity of the product based on manipulation of the reaction parameters.

Mechanistic understanding of Rh-catalyzed N-sulfonylaldimine insertion into aryl C–H bonds

A detailed investigation is presented to understand the catalytic pathway of our recently reported Rh(III)-catalyzed N-tosylaldimine insertion into aryl C–H bonds. Herein, the key intermediates were isolated and determined by X-ray crystallography of their single crystals. The kinetic characterization of each factor in this catalytic reaction was conducted. The studies indicate that N-tosyl aldimine insertion into the C–Rh bonds rather than C–H bond activation or protonolysis is the rate-determining step. These mechanistic insights have significant implications for the development of a more efficient catalytic reaction system to realize the addition of C–H bonds to normal aldehydes and ketones, to achieve sp3 C–H bond activation, and to implement asymmetric catalysis in the near future.

Amberlyst-15–Catalyzed Facile Synthesis of α-Amino Phosphonates

A simple and efficient method has been developed for the synthesis of sulfonamide phosphonates from N-tosyl aldimines and dimethyl trimethylsilyl phosphite at 0 °C in the presence of Amberlyst-15 as a heterogeneous catalyst.

Stereoselective cascade reactions for construction of polyfunctionalised octahydroquinolines via [2C+2C+1C,1N] cyclisation

A conceptually unifying approach for a highly enantio- and diastereoselective synthesis of polyfunctionalised octrahydroquinolines incorporating three contiguous chiral centres is reported. The synthesis involves diphenylprolinol silyl ether-catalysed Michael addition of 1,3-cyclohexanedione to nitroalkenes followed by potassium carbonate-promoted aza-Henry reaction with N-tosyl aldimines, intramolecular hemiaminalisation and dehydration reaction cascade in a one-pot operation.

ChemInform Abstract: Ytterbium(III) Triflate/TMSCI: Efficient Catalyst for Imino Ene Reaction.

[reaction: see text] Ytterbium trifluoromethanesulfonate [Yb(OTf)3] catalyzed the imino ene reaction of N-tosyl aldimine with alpha-methylstyrene to give a homoallylamine in moderate yield. Furthermore, addition of a catalytic amount of chlorotrimethylsilane (TMSCI) dramatically enhanced the imino ene reaction.

Synthesis of cis-3,4-diaryl α-methylene-γ-butyrolactams via sonochemical Barbier-type reaction

A series of cis-3,4-diaryl α-methylene-γ-butyrolactams were synthesized by the addition reaction of 3-phenylallyl bromide with N-tosyl aldimine via sonochemical Barbier-type reaction condition and then followed by the in situ intramolecular amidation. The cis-3,4-diaryl α-methylene-γ-butyrolactam was obtained as the sole regio- and stereoisomeric product when N-tosyl aldimine was used as the substrate whereas the monoaryl α-methylene-γ-butyrolactam was also generated when N-phenyl aldimine was used.

Asymmetric Synthesis of New Chiral β-Amino Acid Derivatives by Mannich-type Reactions of Chiral N-Sulfinyl Imidates with N-Tosyl Aldimines

New chiral beta-(sulfonylamino)sulfinylimidates are synthesized in high overall yield and excellent diastereomeric excess via highly anti-selective Mannich-type reactions of chiral N-tert-butanesulfinyl imidates with N-tosyl aldimines. Deprotection of the beta-(sulfonylamino)sulfinylimidates gave access to enantiopure imidate hydrochlorides in high yields, as useful intermediates for an easy transformation to new chiral beta-sulfonylamino amides upon simple heating in chloroform. Hydrolysis of the imidate hydrochlorides afforded the corresponding chiral beta-sulfonylamino esters with >98% ee as new chiral beta-amino acid derivatives.