651321-57-2

Upstream product

• 495-20-5 (+)-conhydrine 
• 121044-85-7 octa-5,7-dienylamine 
• 121044-85-7 (E)-octa-5,7-dien-1-amine 
• 38700-15-1 triphenyl-(2-pyridylmethyl)phosphonium chloride 
• 17618-94-9 2-(prop-1-en-1-yl)pyridine 
• 161009-85-4 5,6-octadienylamine 

Relevant academic research and scientific papers

Borane-Catalyzed Chemoselective and Enantioselective Reduction of 2-Vinyl-Substituted Pyridines

Herein, we report that highly chemoselective and enantioselective reduction of 2-vinyl-substituted pyridines has been achieved for the first time. The reaction, which uses chiral spiro-bicyclic bisboranes as catalysts and HBpin and an acidic amide as reducing reagents, proceeds through a cascade process involving 1,4-hydroboration followed by transfer hydrogenation of a dihydropyridine intermediate. The retained double bond in the reduction products permits their conversion to natural products and other useful heterocyclic compounds by simple transformations.

Alkyl complexes of lanthanum and samarium supported by a chiral binaphthylamido ligand. Syntheses, structures, and catalytic activity in hydroamination of amino-1,3-dienes

The reactions of (R)-(+)-2,2′-bis(cyclopentylamino)-1,1′- binaphthyldiamine with [Li(THF)n]3[LnMe6] (Ln = La, Sm) in THF at 0 °C depending on the metal ion size result in the formation of trinuclear [(R)-C20H12(NC5H 9)2]Sm[(μ-Me)2Li(THF)2(μ-Me) Li(THF)] (1) or tetranuclear [(R)-C20H12(NC 5H9)2]La{(μ-Me)2Li(THF)[(μ-Me) Li(THF)]2} (2) complexes with methyl ligands μ-bridging lanthanide and lithium atoms. The structures of complexes 1 and 2 were established by single-crystal X-ray diffraction and solution NMR studies. These new complexes were evaluated as catalysts to promote the enantioselective hydroamination of amino-1,3-dienes.

Easy routes towards chiral lithium binaphthylamido catalysts for the asymmetric hydroamination of amino-1,3-dienes and aminoalkenes

The preparation of chiral lithium salts of N,N′-disubstituted binaphthyldiamines and their use as catalysts for asymmetric hydroamination/cyclisation of amino-1,3-dienes and aminoalkenes are reported. Several straightforward methods involving the combinat

Preparation of enantiopure substituted piperidines containing 2-alkene or 2-alkyne Chains: Application to total syntheses of natural quinolizidine- alkaloids

"Chemical Equation Presented" A general method, for the preparation of enantiopure 2-alkene- or 2-alkyne-containing chain substituted piperidines was established by using nonracemic Betti base as a chiral auxiliary. The key step is that the auxiliary residue was removed by a novel base-catalyzed N-debenzylation via a formation of o-quinone methide mechanism in stead, of the traditional hydrogenolysis, by which the alkene or alkyne groups survived. By this method, ten 2-alkene- or 2-alkyne-containing chain substituted piperidines were prepared on the gram scale within a few hours. To demonstrate the efficiency of the method and the versatility of the product, total, syntheses of natural alkaloids (+)-pelletierine((-)-lasubine II, and (-)-cermizine C were achieved by using (S)-2-allyl-N-Bocpiperidine as a versatile building block.

Constrained geometry organoactinides as versatile catalysts for the intramolecular hydroamination/cyclization of primary and secondary amines having diverse tethered C-C unsaturation

A series of "constrained geometry" organoactinide complexes, (CGC)An(NMe)2 (CGC = Me2-Si(η5-Me 4C5)(tBuN); An = Th, 1; U, 2), has been prepared via efficient in situ, two-step protodeamination routes in good yields and high purity. Both 1 and 2 are quantitatively converted to the neutrally charged, solvent-free dichlorides (1-Cl2, 2-Cl2) and slightly more soluble diiodides (1-I2, 2-I2) with excess Me3Si-X (X = Cl, I) in non-coordinating solvents. The new complexes were characterized by NMR spectroscopy, elemental analysis, and (for 1 and 2) single-crystal X-ray diffraction, revealing substantially increased metal coordinative unsaturation vs the corresponding Me2SiCp″ 2AnR2 (Cp″ = η5-Me4C 5; An = Th, R = CH2-(SiMe3), 3; An = U, R = CH2Ph, 4) and Cp′2AnR2 (Cp′ = η5-Me5C5 ; An = Th, R = CH 2(SiMe3), 5; An = U, R = CH2(SiMe3), 6) complexes. Complexes 1-6 exhibit broad applicability for the intramolecular hydroamination of diverse C-C unsaturations, including terminal and internal aminoalkenes (primary and secondary amines), aminoalkynes (primary and secondary amines), aminoallenes, and aminodienes. Large turnover frequencies (N t up to 3000 h-1) and high regioselectivities (≥95%) are observed throughout, along with moderate to high diastereoselectivities (up to 90% trans ring closures). With several noteworthy exceptions, reactivity trends track relative 5f ionic radii and ancillary ligand coordinative unsaturation. Reactivity patterns and activation parameters are consistent with a reaction pathway proceeding via turnover-limiting C=C/C=C insertion into the An-N σ-bond.

Intramolecular Hydroamination/Cyclization of Conjugated Aminodienes Catalyzed by Organolanthanide Complexes. Scope, Diastereo- and Enantioselectivity, and Reaction Mechanism

Organolanthanide complexes of the general type Cp′ 2LnCH(TMS)2 (Cp′ = η5-Me 5C5; Ln = La, Sm, Y; TMS = SiMe3) and CGCSmN(TMS)2 (CGC = Me2Si(η5-Me 4C5)(tBuN)) serve as effective precatalysts for the rapid, regioselective, and highly diastereoselective intramolecular hydroamination/cyclization of primary and secondary amines tethered to conjugated dienes. The rates of aminodiene cyclizations are significantly more rapid than those of the corresponding aminoalkenes. This dienyl group rate enhancement as well as substituent group (R) effects on turnover frequencies is consistent with proposed transition state electronic demands. Kinetic and mechanistic data parallel monosubstituted aminoalkene hydroamination/cyclization, with turnover-limiting C=C insertion into the Ln-N bond to presumably form an Ln-η3 allyl intermediate, followed by rapid protonolysis of the resulting Ln-C linkage. The rate law is first-order in [catalyst] and zero-order in [aminodiene]. However, depending on the particular substrate and catalyst combination, deviations from zero-order kinetic behavior reflect competitive product inhibition or self-inhibition by substrate. Lanthanide ionic radius effects and ancillary ligation effects on turnover frequencies suggest a sterically more demanding Ln-N insertion step than in aminoalkene cyclohydroamination, while a substantially more negative ΔS? implies a more highly organized transition state. Good to excellent diastereoselectivity is obtained in the synthesis of 2,5-trans-disubstituted pyrrolidines (80% de) and 2,6-cis-disubstituted piperidines (99% de). Formation of 2-(prop-1-enyl)piperidine using the chiral C1-symmetric precatalyst (S)-Me2Si(OHF)(CpR* )SmN(TMS)2 (OHF = η5-octahydrofluorenyl; Cp = η5-C5H3; R* = (-)-menthyl) proceeds with up to 71% ee. The highly stereoselective feature of aminodiene cyclization is demonstrated by concise syntheses of naturally occurring alkaloids, (±)-pinidine and (+)-coniine from simple diene precursors.

Highly stereoselective intramolecular hydroamination/cyclization of conjugated aminodienes catalyzed by organolanthanides

Efficient intramolecular hydroamination/cyclization of primary and secondary conjugated aminodienes can be effected by using organolanthanide precatalysts of the type Cp-2LnCH(TMS)2 (Cp- = η5-Me5C5; Ln = La, Sm, Y; TMS = SiMe3) and CGCSmN(TMS)2 (CGC = Me2Si(η5-Me4C5)(tBuN)). The transformation proceeds cleanly (≥ 90% conversion) at 25-60 °C with good rates and high regioselectivities, and with electronic effects leading to significant rate enhancements. Some features of the reaction parallel monosubstituted aminoalkene hydroamination/cyclization, including rate law (zero order in [aminodiene]), and rate enhancements observed with larger lanthanide ionic radii and/or more open catalyst ligation structures. Good to excellent diastereoselectivity is obtained in the synthesis of 2,5-trans-disubstituted pyrrolidines (80% de) and 2,6-cis-disubstituted piperidines (99% de) with using the corresponding α-methyl aminodiene precursors. Formation of 2-(prop-1-enyl)piperidine with the chiral C1-symmetric precatalyst (S)-Me2Si(OHF)(CpR*)SmN(TMS)2 (OHF = η5-octahydrofluorenyl; Cp = η5-C5H3; R* = (-)-menthyl) proceeds with up to 69% ee. Copyright