The dimesitylboron group in organic synthesis. 5. Hetero-atom substituted dimesitylborylmethanes.

Garad, M. V.; Pelter, Andrew; Singaram, Bakthan; Wilson, John W.

doi:10.1016/s0040-4039(00)81485-9

Cited by 30 publications

(7 citation statements)

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“…The 11 B NMR shift of 5 at δ 43.6 is upfield relative to 9a (δ 47.1) due to the enhanced electron density at B . Indeed, this chemical shift value is virtually identical to that reported by Pelter for the similarly substituted acyclic anion . The 1 H and 13 C NMR spectra of 5 at ambient temperature show that the two isopropyl groups are identical due to rapid rotation about the B−N bond.…”

supporting

confidence: 70%

“…8 The reaction of 9a with tBuLi in ether gave a bright yellow solution of anion 5, which on quenching with methyl iodide afforded the expected 2-methyl derivative 9b in 92% yield. The 1 H, 11 B, and 13 C NMR spectra of 5 in THF-d 8 show that this carbanion is strongly stabilized by π-bonding to boron. The BCH group shows a 1 H NMR signal (δ 3.14) and a 13 C NMR signal (δ 60.9) far downfield from those of sp 3 -hybridized organolithium compounds, 9 which indicates that the carbon is sp 2 hybridized.…”

mentioning

confidence: 95%

“…10 Indeed, this chemical shift value is virtually identical to that reported by Pelter for the similarly substituted acyclic anion. 11 The 1 H and 13 C NMR spectra of 5 at ambient temperature show that the two isopropyl groups are identical due to rapid rotation about the B-N bond. As had previously been found for lithium aminoboratabenzenes, incorporation of the boron atom into the aromatic ring of 5 greatly diminishes its ability to form an external π-bond to nitrogen.…”

mentioning

confidence: 98%

“…13 C NMR (90 MHz, THF-d8): δ 22.5 (CH3), 24.1 (CH3′), 47.7 (br, NCH), 50.6 (br NCH′), 123.1,124.0,131.3,134.4 (ArC). 11 B NMR (115.5 MHz, THF-d8): δ 47.1. HRMS (EI, m/z): calcd for C13H20 11 BNS, 233.1410;found, 233.1411.…”

mentioning

confidence: 99%

“…13 C NMR (90 MHz, THF-d8): δ 24.35 (CH3), 24.38 (CH3′), 48.1 (NCH), 60.9 (BCH), 119.0 (Ar), 120.8 (Ar), 123.9 (Ar), 145.2 (BC(Ar)), 152.1 (SC(Ar)). 11 B NMR (115.5 MHz, THF-d8): δ 43.6. 7 Li NMR (140 MHz, THF-d8): δ 3.14.…”

mentioning

confidence: 99%

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1,3-Benzothiaborolide: A New Heteroaromatic Anion

Fang

Kampf

1998

Organometallics

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supporting

confidence: 70%

mentioning

confidence: 95%

mentioning

confidence: 98%

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confidence: 99%

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confidence: 99%

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1,3-Benzothiaborolide: A New Heteroaromatic Anion

Fang

Kampf

1998

Organometallics

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Hydroboration

Zaidlewicz

2000

Kirk-Othmer Encyclopedia of Chemical Technology

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The hydroboration reaction and transformations of its organoborane products are described. The mechanism and the chemo‐, regio‐, and stereoselectivity of the hydroboration reaction are presented, as well as the synthesis and characteristics of the most common hydroborating agents. Transformations of organoboranes may involve carbon‐hetero atom bond formation and lead to stereoselective synthesis of organic halides, amines, aziridines, sulfur, selenium, and mercury compounds. Hydroboration‐protonolysis is a nonocatalytic method of cis‐hydrogenation of multiple bonds. Hydroboration‐oxidation is a standard method for cis‐anti‐Markovnikov hydroxylation of multiple bonds. Carbon‐carbon bond formation can be accomplished by transformation of organoboranes through coupling of groups attached to boron, cross‐coupling of organoboranes with organic halides, organoborate rearrangements providing access to alkynes, ( E )‐ and ( Z )‐alkenes, ( E,E )‐, ( E,Z )‐, ( Z,Z )‐dienes, and enynes. Single‐carbon insertion reactions include carbonylation, cyanidation, and the DCME and related reactions. Other reactions include α‐ and β‐alkylation of carbonyl compounds, the addition of alkynyl, alkenyl, and allylic boranes to aldehydes, leading to proparylic alcohols and stereodefined allylic and homoallylic alcohols, boron‐stabilized carbanions, the boron Wittig reaction, and concerted reactions of allylic and vinylic boranes. Contrathermodynamic isomerization of olefins is discussed. The synthesis of boron‐containing polymers and of isotopically labeled compounds is covered. Asymmetric synthesis via chiral organoboranes is covered in detail.

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Hydroboration

Zaidlewicz

2005

Kirk-Othmer Encyclopedia of Chemical Technology

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The hydroboration reaction and transformations of its organoborane products are described. The mechanism and the chemo‐, regio‐, and stereoselectivity of the uncatalyzed and catalyzed hydroboration reaction are presented, as well as the synthesis and characteristics of the most common hydroborating agents. Transformations of organoboranes may involve carbon–heteroatom bond formation and lead to stereoselective synthesis of organic halides, amines, aziridines, sulfur, selenium, mercury, and zinc compounds. Hydroboration–protonolysis is a nonocatalytic method for cis hydrogenation of multiple bonds. Hydroboration–oxidation is a standard method for cis‐anti‐Markovnikov hydroxylation of multiple bonds, whereas the catalyzed hydroboration may lead to Markovnikov hydroxylation. Contrathermodynamic isomerization of olefins is discussed. Carbon–carbon bond formation can be accomplished by transformation of organoboranes through coupling of groups attached to boron, cross‐coupling of organoboranes with organic halides and triflates, organoborate rearrangements providing access to alkynes, dienes, and enynes. Single‐carbon insertion reactions, make possible homologation of organoboranes. Other transformations include α‐alkylation of carbonyl compounds, the boron Wittig reaction, concerted reactions of allylic and vinylic boranes, allylboration, allenylboration and propargylboration of aldehydes leading to stereodefined allylic, homoallylic, and allenyl alcohols. The synthesis of boron‐containing polymers and isotopically labeled compounds is covered. Asymmetric synthesis via chiral organoboranes and stereodirected enolboration–aldolization is described.

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The dimesitylboron group in organic synthesis. 5. Hetero-atom substituted dimesitylborylmethanes.

Cited by 30 publications

References 2 publications

1,3-Benzothiaborolide: A New Heteroaromatic Anion

1,3-Benzothiaborolide: A New Heteroaromatic Anion

Hydroboration

Hydroboration

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