A versatile iodo(iii)etherification of terminal ethynylsilanes using BF3–OiPr2 and alkyl benzyl ethers

2021 ◽  
Author(s):  
Takuya Matsumoto ◽  
Hiroshi Hagiyama ◽  
Kanetsugu Kuribayashi ◽  
Kazuhito Hioki ◽  
Hikaru Fujita ◽  
...  
Keyword(s):  
Benzyl Ether ◽  
Alkoxyl Group ◽  
Group Transfer ◽  
Benzyl Ethers

BF3–OiPr2 and alkyl benzyl ether combining system enables a chemoselective alkoxyl group transfer in the synthesis of (E)-α-silyl-β-alkoxyvinyl-λ3-iodanes.

Visible Light-Mediated Oxidative Debenzylation

2020 ◽  
Author(s):  
Cristian Cavedon ◽  
Eric T. Sletten ◽  
Amiera Madani ◽  
Olaf Niemeyer ◽  
Peter H. Seeberger ◽  
...  
Keyword(s):  
Reaction Time ◽  
Visible Light ◽  
Functional Groups ◽  
Continuous Flow ◽  
Protecting Groups ◽  
Benzyl Ether ◽  
Complex Molecules ◽  
Protective Groups ◽  
Benzyl Ethers ◽  
Harsh Conditions

Protecting groups are key in the synthesis of complex molecules such as carbohydrates to distinguish functional groups of similar reactivity. The harsh conditions required to cleave stable benzyl ether protective groups are not compatible with many other protective and functional groups. The mild, visible light-mediated debenzylation disclosed here renders benzyl ethers orthogonal protective groups. Key to success is the use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as stoichiometric or catalytic photooxidant such that benzyl ethers can be cleaved in the presence of azides, alkenes, and alkynes. The reaction time for this transformation can be reduced from hours to minutes in continuous flow. <br>

Metal-free synthesis of 1H-isochromenes via benzyl ether-assisted, electrophilic addition of diaryl acetylenes

2021 ◽  
Author(s):  
Tzu-Hsuan Kuan ◽  
Trimurtulu Kotipalli ◽  
Cheng-Chun Chen ◽  
Duen-Ren Hou
Keyword(s):  
Intramolecular Cyclization ◽  
Room Temperature ◽  
Electrophilic Addition ◽  
Benzyl Ether ◽  
Metal Free ◽  
Benzyl Ethers ◽  
The Stability ◽  
Diaryl Acetylenes

Bromotrimethylsilane (TMSBr) promoted, intramolecular cyclization of (o-arylethynyl)benzyl ethers to form 1H-isochromenes at room temperature is reported. Further studies indicated that the stability of vinyl carbocations is crucial, similar to the...

Synthesis and Herbicidal Activity of Modified Monoterpenes Structurally Similar to Cinmethylin

Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Steven F. Vaughn ◽  
Gayland F. Spencer
Keyword(s):  
Petri Dish ◽  
Herbicidal Activity ◽  
Benzyl Ether ◽  
Weed Species ◽  
Test Species ◽  
Oxygenated Monoterpenes ◽  
Radicle Elongation ◽  
Benzyl Ethers ◽  
Germination And Growth ◽  
Derivatives Of

The preemergence herbicide cinmethylin is a benzyl ether derivative of the monoterpene 1,4-cineole. Other oxygenated monoterpenes (carvone, citronellol, fenchone, geraniol, and pulegone) were previously found to inhibit the germination and growth of several weed species while exhibiting low phytotoxicity to soybean. Benzyl ether derivatives of these oxygenated monoterpenes were synthesized and examined for preemergence and postemergence activity towards corn, soybean, wheat, and velvetleaf. Benzyl pulegyl ether exhibited the most preemergence activity when applied directly to the soil, completely inhibiting wheat and velvetleaf emergence at 1.0 kg ha−1while reducing soybean emergence 80%. Several of the benzyl ethers were more inhibitory to velvetleaf radicle elongation relative to cinmethylin but less inhibitory to corn and wheat radicle elongation in petri dish bioassays. Several of the benzyl ethers exhibited limited postemergence activity when applied at 1.0 kg ha−1to seedlings of the test species 10 d after emergence. The benzyl ether derivatives demonstrated altered selectivity and sensitivity as compared to the parent compounds and cinmethylin.

scholarly journals Mono- and disubstitutions of (hepta-2,5-diyne-1,7-diol) bis(dicobalt) derivatives — Selectivity in Nicholas reactions

2004 ◽  
Vol 82 (2) ◽  
pp. 366-374 ◽  
Author(s):  
Richard Guo ◽  
Romelo Gibe ◽  
James R Green
Keyword(s):  
Methyl Ether ◽  
Lewis Acids ◽  
Benzyl Ether ◽  
Nicholas Reaction ◽  
Benzyl Ethers ◽  
Alkyne Complexes ◽  
Derivatives Of ◽  
Alcohol Derivative ◽  
Ether Complex ◽  
Ether Alcohol

Bis(hexacarbonyldicobalt) complexes of benzyl ether – methyl ether or benzyl ether – acetate derivatives of hepta-2,5-diyne-1,7-diols undergo selective Lewis-acid-mediated Nicholas reactions with enol silanes, silyl ketene acetals, and allylstannanes, preferentially replacing the methyl ether or acetate function. Hydride nucleophiles are similarly incorporated selectively using a benzyl ether – alcohol derivative. Subsequent Nicholas reaction at the benzyloxy-bearing site may be accomplished with an identical or a different nucleophile, affording skipped 1,4-diyne-Co4(CO)12 complexes. In instances of lower selectivity for monosubstitution reactions with benzyl ethers, reverting to the use of a menthyl ether – methyl ether complex gives much improved selectivity for methyl ether substitution.Key words: cobalt alkyne complexes, Nicholas reaction, Lewis acids, 1,4-diynes.

scholarly journals Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C

2013 ◽  
Vol 9 ◽  
pp. 74-78 ◽  
Author(s):  
Abhishek Santra ◽  
Tamashree Ghosh ◽  
Anup Kumar Misra
Keyword(s):  
Room Temperature ◽  
Transfer Hydrogenation ◽  
Benzyl Ether ◽  
Catalytic Transfer Hydrogenation ◽  
Excellent Yield ◽  
Benzyl Ethers ◽  
Catalytic Transfer

Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH3OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.

Depolymerizable poly(benzyl ether)-based materials for selective room temperature recycling

2015 ◽  
Vol 17 (9) ◽  
pp. 4541-4545 ◽  
Author(s):  
Matthew S. Baker ◽  
Hyungwoo Kim ◽  
Michael G. Olah ◽  
Gregory G. Lewis ◽  
Scott T. Phillips
Keyword(s):  
Room Temperature ◽  
Quinone Methide ◽  
Benzyl Ether ◽  
Temperature Separation ◽  
Benzyl Ethers

Straightforward modifications to quinone methide monomers creates self-immolative poly(benzyl ethers) that enable room temperature separation and recycling of plastics.

scholarly journals Visible Light-Mediated Oxidative Debenzylation

2020 ◽  
Author(s):  
Cristian Cavedon ◽  
Eric T. Sletten ◽  
Amiera Madani ◽  
Olaf Niemeyer ◽  
Peter H. Seeberger ◽  
...  
Keyword(s):  
Reaction Time ◽  
Visible Light ◽  
Functional Groups ◽  
Continuous Flow ◽  
Protecting Groups ◽  
Benzyl Ether ◽  
Complex Molecules ◽  
Protective Groups ◽  
Benzyl Ethers ◽  
Harsh Conditions

Protecting groups are key in the synthesis of complex molecules such as carbohydrates to distinguish functional groups of similar reactivity. The harsh conditions required to cleave stable benzyl ether protective groups are not compatible with many other protective and functional groups. The mild, visible light-mediated debenzylation disclosed here renders benzyl ethers orthogonal protective groups. Key to success is the use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as stoichiometric or catalytic photooxidant such that benzyl ethers can be cleaved in the presence of azides, alkenes, and alkynes. The reaction time for this transformation can be reduced from hours to minutes in continuous flow. <br>

A Facile, Efficient and Selective Deprotection of P - Methoxy Benzyl Ethers Using Zinc (II) Trifluoromethanesulfonate

2019 ◽  
Vol 16 (12) ◽  
pp. 955-958
Author(s):  
Reddymasu Sireesha ◽  
Reddymasu Sreenivasulu ◽  
Choragudi Chandrasekhar ◽  
Mannam Subba Rao
Keyword(s):  
Room Temperature ◽  
Protecting Groups ◽  
Side Reactions ◽  
Reaction Conditions ◽  
Acid Sensitivity ◽  
Time Period ◽  
Protective Groups ◽  
Benzyl Ethers ◽  
Last Stage ◽  
Zinc Triflate

: Deprotection is significant and conducted over mild reaction conditions, in order to restrict any more side reactions with sensitive functional groups as well as racemization or epimerization of stereo center because the protective groups are often cleaved at last stage in the synthesis. P - Methoxy benzyl (PMB) ether appears unique due to its easy introduction and removal than the other benzyl ether protecting groups. A facile, efficient and highly selective cleavage of P - methoxy benzyl ethers was reported by using 20 mole% Zinc (II) Trifluoromethanesulfonate at room temperature in acetonitrile solvent over 15-120 min. time period. To study the generality of this methodology, several PMB ethers were prepared from a variety of substrates having different protecting groups and subjected to deprotection of PMB ethers using Zn(OTf)2 in acetonitrile. In this methodology, zinc triflate cleaves only PMB ethers without affecting acid sensitivity, base sensitivity and also chiral epoxide groups.

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