New sterically hindered bis-catechol, bis- o -quinone and its bis-triphenylantimony(v) bis-catecholate. 3,5-Di- tert -butyl-6-methoxymethylcatechol as alkylating agent

2018 ◽  
Vol 28 (1) ◽  
pp. 76-78 ◽  
Author(s):  
Maxim V. Arsenyev ◽  
Tatyana V. Astafeva ◽  
Evgeny V. Baranov ◽  
Andrey I. Poddelsky ◽  
Sergey A. Chesnokov
Keyword(s):  
Alkylating Agent ◽  
Tert Butyl ◽  
Sterically Hindered

Bis(ether) derivatives of tetrakis(2-hydroxyphenyl)ethene — Direct synthesis of (E)- and (Z)-bis(2-hydroxyphenyl)-bis(2-methoxyphenyl)ethene via the McMurry olefination reaction

2006 ◽  
Vol 84 (10) ◽  
pp. 1250-1253 ◽  
Author(s):  
Mee-Kyung Chung ◽  
Paul Fancy ◽  
Jeffrey M Stryker
Keyword(s):  
Supramolecular Chemistry ◽  
Direct Synthesis ◽  
Protecting Groups ◽  
Tert Butyl ◽  
Orthogonal Protection ◽  
Protection Strategies ◽  
Titanium Trichloride ◽  
Sterically Hindered ◽  
Derivatives Of

The direct synthesis of sterically hindered, partially etherified derivatives of tetrakis(2-hydroxyphenyl)ethene is reported by using the McMurry reductive olefination reaction on a range of differentially substituted 2,2′-dialkoxy benzophenone substrates. Three orthogonal protection strategies are demonstrated, incorporating β-silylethyl, 3-butenyl, and tert-butyl protecting groups, respectively, into the starting benzophenones. The latter proved most efficient, with both the McMurry coupling and deprotection steps occurring concomitantly under the McMurry conditions to directly yield the desired bis(2-hydroxyphenyl)-bis(2-methoxyphenyl)ethene as a 1:1 mixture of E- and Z-diastereoisomers.Key words: preorganized polyaryloxide ligands, McMurry olefination, titanium trichloride, supramolecular chemistry, tetrakis(2-hydroxyphenyl)ethene, 2,2′-disubstituted benzophenone.

A new sterically hindered asymmetric zinc phthalocyanine as an efficient sensitizer for dye-sensitized solar cells

2021 ◽  
Author(s):  
Kevser Harmandar ◽  
Kevin Granados-Tavera ◽  
Merve Keskin ◽  
Mehmet Nebioğlu ◽  
İlkay Şişman ◽  
...  
Keyword(s):  
Solar Cells ◽  
Carboxylic Acid ◽  
Dye Sensitized Solar Cells ◽  
Zinc Phthalocyanine ◽  
Tert Butyl ◽  
Dye Sensitized ◽  
Anchoring Group ◽  
Sterically Hindered ◽  
Sensitized Solar Cells

An asymmetric zinc phthalocyanine dye (KH1) bearing three 2,6-di-tert-butyl-4-methylphenoxy donor groups and carboxylic acid anchoring group was synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). The DSSC based on...

Study on the enolization of alkylation of cis and trans 2-tert-5-X-1,3-dioxanes (X = CO2CH3, CHO, COPh, NO2, and CN). Evidence for stereoelectronic control

1986 ◽  
Vol 64 (9) ◽  
pp. 1788-1794 ◽  
Author(s):  
Alexis Ndibwami ◽  
Pierre Deslongchamps
Keyword(s):  
Alkylating Agent ◽  
Trans Isomers ◽  
Tert Butyl ◽  
Cyclohexane Carboxylate ◽  
Stereoelectronic Control ◽  
Cis And Trans

Alkylation of 2-tert-butyl-5-X-1,3-dioxanes (X = CO2CH3, COPh, and NO2) was studied. Products resulting from an equatorial approach of the alkylating agent are preferentially formed when X = CO2CH3 and NO2. Also, the cis isomers that have an equatorial hydrogen at C-5 were found to deprotonate at a faster rate than the trans isomers when X = CO2CH3, COPh, CHO, and CN. These results are compared with those obtained with methyl 2-tert-butyl cyclohexane carboxylate and are interpreted by taking into account stereoelectronic principles.

Alkylation of camphor imines of glycinates. Diastereoselectivity as a function of electronic factors in the alkylating agent

1986 ◽  
Vol 64 (4) ◽  
pp. 726-731 ◽  
Author(s):  
John M. McIntosh ◽  
Pratibha Mishra
Keyword(s):  
Transition State ◽  
Alkylating Agent ◽  
Alkylating Agents ◽  
Type Systems ◽  
Alkyl Halides ◽  
State Interaction ◽  
Tert Butyl ◽  
Ca 50

Alkylation of the (R)-camphor imine of tert-butyl glycinate with a variety of alkylating agents gave diastereoselectivities ranging from 0–100%. Simple alkyl halides larger than methyl give de's (diastereomeric excesses) of ca. 50% whereas those derived from allylic type systems afford de's of 75–100%. The results are best explained by invoking a transition state interaction between the π system of the alkylating agent and the imine which, for steric reasons, requires alkylation to occur from the pro-R face.

Interaction of 3,5-di-tert-butyl-o-benzoquinone with secondary amines—a pathway to new sterically hindered N,N-disubstituted o-aminophenols

Tetrahedron ◽  
2011 ◽  
Vol 67 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Vladimir Cherkasov ◽  
Nikolay Druzhkov ◽  
Tatiana Kocherova ◽  
Georgii Fukin ◽  
Andrey Shavyrin
Keyword(s):  
Secondary Amines ◽  
Tert Butyl ◽  
Sterically Hindered
Sign in / Sign up

Export Citation Format

Share Document