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Updated: Jun 28, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
09:58

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

Published on: February 24, 2015

ボリル置換オルガントリフローロボラートにおけるオートホーナル反応性

Gary A Molander1, Deidre L Sandrock

  • 1Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA. gmolandr@sas.upenn.edu

Journal of the American Chemical Society
|November 5, 2008
PubMed
まとめ

新しい水酸化法では,オルガノトリフルオロボラートからディボラ中間産物を作ります. これにより,選択的クロスカップリングが可能になり,トリフッ素ボラートはさらなる反応のために保存され,複雑な分子合成が簡素化されます.

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Regioselectivity and Stereochemistry of Hydroboration

A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
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ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
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Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

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Hydroboration-Oxidation of Alkenes

In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
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ortho–para-Directing Deactivators: Halogens

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Regioselectivity of Electrophilic Additions-Peroxide Effect

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