Reduction of Monobenzylic Alcohols with Sodium Borohydride/Trifluoroacetic Acid

Nutaitis, Charles F.; Bernardo, Joseph E.

doi:10.1080/00397919008244895

Cited by 18 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 H NMR (250 MHz, CDCl 3 ) δ 6.85 (dd, 8H), 3.85 (s, 6H); 13 C NMR (62.5 MHz, CDCl 3 ) 23.3 (septet), 42.6, 55.2, 111.9, 129.6, 139.1, 157.3. The deuterated precursor, 4-methoxycumene- d 6 , was prepared by Grignard addition of acetone- d 6 to 4-bromoanisole and subsequent reduction of the corresponding alcohol using trifluoroacetic acid and sodium borohydride . The alcohols, methanol, ethanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, and tert -butyl alcohol, were of spectroscopic grade (Aldrich) and used as received.…”

Section: Methodsmentioning

confidence: 99%

Absolute Reactivity of the 4-Methoxycumyl Cation in Non-Acid Zeolites

2000

View full text Add to dashboard Cite

The reactivity of the 4-methoxycumyl cation in a series of alkali metal cation-exchanged zeolites (LiY, NaY, KY, RbY CsY, NaX, NaMor, and Naβ) in the absence and presence of coadsorbed alcohols and water is examined using nanosecond laser flash photolysis. In dry zeolites, the absolute reactivity of the carbocation is found to be strongly dependent on the nature of the alkali counterion, the Si/Al ratio, and the framework morphology, with the lifetime of the carbocation in Naβ being almost 10000-fold longer than in CsY. The results suggest a mechanism for carbocation decay involving direct participation of the zeolite framework as a nucleophile, leading to the generation of a framework-bound alkoxy species. Intrazeolite addition reactions of alcohols and water to the 4-methoxycumyl cation can be described in terms of both dynamic and static quenching involving molecular diffusion through the heterogeneous topology and rapid coupling between the alcohol and the carbocation encapsulated within the same cavity. The dynamics of the quenching reactions are different from similar reactions in homogeneous solution due to both the passive and active influences of the zeolite environment. In a passive sense, the zeolite decreases the reactivity of the nucleophilic quencher by hindering molecular diffusion. However, the zeolite actively promotes the efficiency of intracavity coupling by enhancing the deprotonation of the oxonium ion intermediate, allowing the reaction to go to completion.

show abstract

Section: Methodsmentioning

confidence: 99%

Absolute Reactivity of the 4-Methoxycumyl Cation in Non-Acid Zeolites

2000

View full text Add to dashboard Cite

show abstract

“…Upon acidic workup of the reaction mixture deprotection of the phenolic hydroxy function occurred, affording the alcohol 349 in 91% yield. The hydroxy group at the benzylic position was removed via utilization of combination of NaBH 4 and TFA in THF, 357 to give (À)-centrolobine 342 in 73% yield. 358 Kusumi and co-workers initially in 2008, isolated the secondary metabolites, aspergillides C, from a marine-derived fungus, Aspergillus ostianus strain 01F313.…”

Section: Hetero Diels-alder (Hda) Reactionmentioning

confidence: 99%

Recent applications of the hetero Diels–Alder reaction in the total synthesis of natural products

et al. 2015

View full text Add to dashboard Cite

show abstract

“…It is effective in removing the hydroxyl group in di-and triaryl methanols (Gribble et al 1977) and in monoaryl benzylic alcohols (Nutaitis and Bernardo 1990) and in removing the α-carbonyl group in diarylketones (Gribble et al 1978). It is effective in removing the hydroxyl group in di-and triaryl methanols (Gribble et al 1977) and in monoaryl benzylic alcohols (Nutaitis and Bernardo 1990) and in removing the α-carbonyl group in diarylketones (Gribble et al 1978).…”

Section: Ionic Hydrogenation With Trifluoroacetic Acid and Sodium Bormentioning

confidence: 99%

A New Approach Towards the Yellowing Inhibition of Mechanical Pulps. Part I: Selective Removal of α-Hydroxyl and α-Carbonyl Groups in Lignin Model Compounds

Hu¹,

Leary²,

Wong³

1999

Holzforschung

View full text Add to dashboard Cite

Summary The α-hydroxyl group in lignin model compounds 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol (1) and 1-(4-hydroxy-3-methoxyphenyl)ethanol (3), and the α-carbonyl group in 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)ethan-1-one (5) are removed by treatment of the model compounds with trifluoroacetic acid (CF3CO OH) and triethylsilane (Et3sih) in methylene chloride. The reaction is highly chemoselective and it tolerates the lignin γ-hydroxyl group, phenol and β-O-4-aryl ether linkage. The α-hydroxyl group in 1 has also been removed with triethylsilane in aqueous trifluoroacetic acid (CF3CO OH : H2o = 75 : 25). The combination of trifluoroacetic acid and sodium borohydride, or sodium triacetoxyborohydride, is also effective in removing the α-carbonyl group in 5 and the α-hydroxyl group in lignin model compound 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)ethanol (7) and in milled wood lignin. The selective removal of the lignin α-hydroxyl and α-carbonyl groups may potentially be used, in conjunction with the protection of the lignin phenol, to inhibit the light and/or heat-induced yellowing of mechanical pulps.

show abstract

Reduction of Monobenzylic Alcohols with Sodium Borohydride/Trifluoroacetic Acid

Cited by 18 publications

References 2 publications

Absolute Reactivity of the 4-Methoxycumyl Cation in Non-Acid Zeolites

Absolute Reactivity of the 4-Methoxycumyl Cation in Non-Acid Zeolites

Recent applications of the hetero Diels–Alder reaction in the total synthesis of natural products

A New Approach Towards the Yellowing Inhibition of Mechanical Pulps. Part I: Selective Removal of α-Hydroxyl and α-Carbonyl Groups in Lignin Model Compounds

Contact Info

Product

Resources

About