Unusual Preference for Ketone and Reversal of Chemoselectivity in Lewis Acid-Catalyzed Aldol Reaction of Ketene Silyl Acetal

1998 ◽  
Vol 63 (26) ◽  
pp. 9739-9745 ◽  
Author(s):  
Jian-xie Chen ◽  
Katsumasa Sakamoto ◽  
Akihiro Orita ◽  
Junzo Otera
Keyword(s):  
Lewis Acid ◽  
Aldol Reaction ◽  
Acid Catalyzed

Mucohalic Acid in Lewis Acid Catalyzed Mukaiyama Aldol Reaction: A Concise Method for Highly Functionalized γ-Substituted γ-Butenolides.

ChemInform ◽  
2005 ◽  
Vol 36 (28) ◽  
Author(s):  
Paul Angell ◽  
Ji Zhang ◽  
Daniel Belmont ◽  
Timothy Curran ◽  
James G. Davidson
Keyword(s):  
Lewis Acid ◽  
Aldol Reaction ◽  
Mukaiyama Aldol Reaction ◽  
Mukaiyama Aldol ◽  
Acid Catalyzed

Assembly of tricyclic compounds that include the spiro[4.4]nonane subunit

1997 ◽  
Vol 75 (6) ◽  
pp. 656-664 ◽  
Author(s):  
Pei-Ying Liu ◽  
Yong-Jin Wu ◽  
D. Jean Burnell
Keyword(s):  
Double Bond ◽  
Lewis Acid ◽  
Aldol Reaction ◽  
Tricyclic Compounds ◽  
Acid Catalyzed ◽  
Cyclohexenone Derivatives ◽  
Geminal Acylation

Spiroannulation of ketals derived from unsaturated cyclohexenone derivatives by the Lewis acid-catalyzed reaction of 1,2-bis((trimethylsilyl)oxy)cyclobutene 5 led to spiro[4.5]decene-diones 9 and 30. These were transformed into spiro[4.4]nonene derivatives 25 and 35/36 via similar sequences involving ozonolysis and aldol ring reclosure. Reduction of an annular double bond allowed facile closure of a third ring, also by an aldol reaction. This work led to a single oxygenated angular triquinane 28 from 9, and to the tricyclo[6.2.1.01,5]undecane derivative 41 from 30. An oxatricyclo[5.3.1.01,5]undecane derivative 19 was also obtained from 9. Keywords: spiroannulation, geminal acylation, sesquiterpene synthesis.

Mucohalic acid in Lewis acid catalyzed Mukaiyama aldol reaction: a concise method for highly functionalized γ-substituted γ-butenolides

2005 ◽  
Vol 46 (12) ◽  
pp. 2029-2032 ◽  
Author(s):  
Paul Angell ◽  
Ji Zhang ◽  
Daniel Belmont ◽  
Timothy Curran ◽  
James G. Davidson
Keyword(s):  
Lewis Acid ◽  
Aldol Reaction ◽  
Mukaiyama Aldol Reaction ◽  
Mukaiyama Aldol ◽  
Acid Catalyzed

ChemInform Abstract: Unusual Preference for Ketone and Reversal of Chemoselectivity in Lewis Acid-Catalyzed Aldol Reaction of Ketene Silyl Acetal.

ChemInform ◽  
2010 ◽  
Vol 30 (23) ◽  
pp. no-no
Author(s):  
Jian-xie Chen ◽  
Katsumasa Sakamoto ◽  
Akihiro Orita ◽  
Junzo Otera
Keyword(s):  
Lewis Acid ◽  
Aldol Reaction ◽  
Acid Catalyzed

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

scholarly journals Comparison of Corn Stover Pretreatments with Lewis Acid Catalyzed Choline Chloride, Glycerol and Choline Chloride-Glycerol Deep Eutectic Solvent

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1170
Author(s):  
Yuan Zhu ◽  
Benkun Qi ◽  
Xinquan Liang ◽  
Jianquan Luo ◽  
Yinhua Wan
Keyword(s):  
Corn Stover ◽  
Lewis Acid ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Enzymatic Saccharification ◽  
Glycerol Solution ◽  
Cellulose Conversion ◽  
Biomass Processing ◽  
Acid Catalyzed ◽  
Highly Correlated

Herein, corn stover (CS) was pretreated by less corrosive lewis acid FeCl3 acidified solutions of neat and aqueous deep eutectic solvent (DES), aqueous ChCl and glycerol at 120 °C for 4 h with single FeCl3 pretreatment as control. It was unexpected that acidified solutions of both ChCl and glycerol were found to be more efficient at removing lignin and xylan, leading to higher enzymatic digestibility of pretreated CS than acidified DES. Comparatively, acidified ChCl solution exhibited better pretreatment performance than acidified glycerol solution. In addition, 20 wt% water in DES dramatically reduced the capability of DES for delignification and xylan removal and subsequent enzymatic cellulose saccharification of pretreated CS. Correlation analysis showed that enzymatic saccharification of pretreated CS was highly correlated to delignification and cellulose crystallinity, but lowly correlated to xylan removal. Recyclability experiments of different acidified pretreatment solutions showed progressive decrease in the pretreatment performance with increasing recycling runs. After four cycles, the smallest decrease in enzymatic cellulose conversion (22.07%) was observed from acidified neat DES pretreatment, while the largest decrease (43.80%) was from acidified ChCl pretreatment. Those findings would provide useful information for biomass processing with ChCl, glycerol and ChCl-glycerol DES.

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