An effective and selective conjugate propargylation reaction of stannylallenes to .alpha.,.beta.-unsaturated carbonyl compounds and .alpha.-nitro olefins

Hoshino, Junichi; Nishi, Koichi; Matsuda, Satoshi; Akai, Shuji; Tamura, Yasumitsu; Kita, Yasuyuki

doi:10.1021/jo00303a019

Cited by 49 publications

(25 citation statements)

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“…Methyl esters 10b-d were synthesized by refluxing the corresponding acids in MeOH, in the presence of a catalytic amount of sulfuric acid. Nitro derivatives 3a, [15] 3b, [16] 3e, [17] 3h, [18] 3i, [19] 5, [20] 7, [20] 9, [20] and 11a, [21] are known compounds, but essential characterization data ( 1 H NMR, 13 C NMR and GC-EI-MS) were reported for clarity, whereas adducts 3c, 3d, 3f, 3g, and 11b-d are new products.…”

Section: Methodsmentioning

confidence: 99%

Polystyryl‐BEMP as an Efficient Recyclable Catalyst for the Nucleophilic Addition of Nitroalkanes to α,β‐Unsaturated Carbonyl Compounds under Solvent‐Free Conditions

et al. 2008

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2-tert-Butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine supported on polystyrene (PS-BEMP) is an efficient catalyst for the addition of nitroalkanes (1-1.5 equiv.) to a,b-unsaturated carbonyl compounds (1.0 equiv.) in the absence of a reaction medium (solvent-free conditions). The corresponding g-nitro carbonyl compounds have been isolated in excellent yields but the catalyst can be satisfactorily recovered and used for only 3 times due to the magnetic stirring which caused crunching of the catalyst beads thus hampering its complete recovery. To optimize the catalysts reuse and improve the environmental efficacy of solvent-free conditions, the first solvent-free cyclic continuous-flow reactor has been set up. This reactor has allowed the product to be isolated in an almost quantitative yield by using a very small amount of organic solvent, making the recovery and reuse of the catalyst efficient and reproducible.

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Section: Methodsmentioning

confidence: 99%

Polystyryl‐BEMP as an Efficient Recyclable Catalyst for the Nucleophilic Addition of Nitroalkanes to α,β‐Unsaturated Carbonyl Compounds under Solvent‐Free Conditions

et al. 2008

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“…In contrast to the analogous Danheiser's studies on allenylsilanes resulting in cyclopentene derivatives, cyclic and acyclic substrates reacted with organotin compounds to furnish propargylated ketones 56 with good yields. 29 Michael addition could also be successfully accomplished with a-nitroalkenes; a-unsubstituted and a-alkylated substrates produced synthetically interesting b-propargylic nitroalkanes 58 and a-propargylic ketones 59, respectively (Scheme 13, Tables 24 and 25).…”

Section: Tinmentioning

confidence: 99%

2.05 Propargyl and Allenyl Organometallics

Yamamoto

Usanov

2014

Comprehensive Organic Synthesis II

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“…Accordingly, we concentrated on the nucleophilic component, aiming to increase the nucleophilicity 19 of the allene toward the oxocarbenium ion by using allenylstannane 24 20 in place of allenylsilane 22. To our satisfaction, the addition proceeded very smoothly with concomitant complete protiodesilylation, delivering terminal alkyne 25 in excellent yield (Scheme 8).…”

Section: Synthesis Of Amphidinolide T1: Assembly Of C1-c12 Fragmentmentioning

confidence: 99%

Total Syntheses of Amphidinolides T1 and T4 via Catalytic Stereoselective, Reductive Macrocyclizations.

2005

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Described in this work are total syntheses of amphidinolides T1 and T4 using two nickel-catalyzed reductive coupling reactions of alkynes, with an epoxide in one case (intermolecular) and with an aldehyde in another (intramolecular). The latter was used to effect a macrocyclization, form a C-C bond and install a stereogenic center with >10:1 selectivity in both natural product syntheses. Alternative approaches in which intermolecular alkyne-aldehyde reductive coupling reactions would serve to join key fragments were investigated and are also discussed; it was found that macrocyclization (i.e. intramolecular alkyne-aldehyde coupling) was superior in several respects (diastereoselectivity, yield, and length of syntheses). Alkyne-epoxide reductive couplings were instrumental in the construction of key fragments corresponding to approximately half of the molecule of both natural products. In one case (T4 series), the alkyne-epoxide coupling exhibited very high site selectivity in a coupling of a diyne. A model for the stereoselectivity observed in the macrocyclizations is also proposed.

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An effective and selective conjugate propargylation reaction of stannylallenes to .alpha.,.beta.-unsaturated carbonyl compounds and .alpha.-nitro olefins

Cited by 49 publications

References 0 publications

Polystyryl‐BEMP as an Efficient Recyclable Catalyst for the Nucleophilic Addition of Nitroalkanes to α,β‐Unsaturated Carbonyl Compounds under Solvent‐Free Conditions

Polystyryl‐BEMP as an Efficient Recyclable Catalyst for the Nucleophilic Addition of Nitroalkanes to α,β‐Unsaturated Carbonyl Compounds under Solvent‐Free Conditions

2.05 Propargyl and Allenyl Organometallics

Total Syntheses of Amphidinolides T1 and T4 via Catalytic Stereoselective, Reductive Macrocyclizations.

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