Reaction of dimethoxycarbene with strained cyclic carbonyl compounds

2000 ◽  
Vol 78 (9) ◽  
pp. 1194-1203
Author(s):  
Paul C Venneri ◽  
John Warkentin
Keyword(s):  
Carbonyl Group ◽  
Carbonyl Compounds ◽  
Ring Expansion ◽  
Carbonyl Groups

A cyclopropanone, a cyclopropenone, cyclobutanones, a cyclobutane-1,3-dione, and a cyclobutene-1,2-dione reacted with dimethoxycarbene to afford acetals of the next larger ring by formal insertion of the carbene into a C—C bond α to the carbonyl group. When either of two saturated α-ring carbons could be involved in the process, the ring expansion was selective, affording primarily the product of apparent insertion into the more substituted ring bond. With 2,3-dimethoxycyclobutene-1,2-dione, insertion occurred between the carbonyl groups and with β-propiolactone it occurred at the lactone bond. β-Propiolactam, however, reacted by insertion of the carbene into the N—H bond.Key words: β-propiolactone, cyclobutanone, cyclobutananedione, cyclopropanone, dialkoxycarbene.

Selective reduction of less reactive carbonyl groups in the presence of diborane and sodium bisulfite on silica gel

1990 ◽  
Vol 68 (5) ◽  
pp. 720-724 ◽  
Author(s):  
Teiji Chihara ◽  
Tamie Wakabayasi ◽  
Kazuo Taya ◽  
Haruo Ogawa
Keyword(s):  
Carbonyl Group ◽  
Carbonyl Compound ◽  
Silica Gel ◽  
Carbonyl Compounds ◽  
Selective Reduction ◽  
Aromatic Aldehydes ◽  
Sodium Bisulfite ◽  
Carbonyl Groups ◽  
Selective Reaction ◽  
Reactive Carbonyl

The less reactive carbonyl group of a mixture of reducible groups of carbonyl compounds was preferentially reduced with diborane on silica gel by first forming an adduct of the more reactive carbonyl group with sodium bisulfite. For example, 4-acetylbenzaldehyde could be converted to 4-(1-hydroxylethyl)benzaldehyde in 93% selectivity; in a mixture of 4-phenyl-acetophenone and 4-phenylbenzaldehyde, biphenylethanol was preferentially formed in 95% yield with 16% yield of 4-phenylbenzyl alcohol. Silica gel and sodium bisulfite were essential for this selective reaction. Aliphatic and aromatic aldehydes and unhindered cyclohexanones could be selectively protected by this method. Keywords: sodium bisulfite, silica gel, carbonyl compound, selective reduction, diborane.

Article

1998 ◽  
Vol 76 (4) ◽  
pp. 490-497
Author(s):  
Okba Saied ◽  
Benoit Bachand ◽  
James D Wuest
Keyword(s):  
Carbonyl Group ◽  
Carbonyl Compounds ◽  
Lewis Acids ◽  
Carbonyl Oxygen ◽  
The Other ◽  
Keto Group ◽  
Carbonyl Groups ◽  
Lone Pairs ◽  
Related Compounds ◽  
Oxygen Atoms

Carbonyl oxygen atoms have two formal lone pairs of electrons. In principle, both can be used simultaneously to form complexes with two or more Lewis acids. This multiple coordination promises to have a variety of interesting consequences; unfortunately, however, complexes of carbonyl compounds with multiple Lewis acids are extremely rare. To promote multiple coordination, we have made a series of symmetric ketodiesters and related compounds in which the carbonyl group of a ketone is flanked by two additional sites of Lewis basicity. In such compounds, the flanking bases and both lone pairs of the central ketone are available for binding two equivalents of suitable Lewis acids, thereby producing symmetric double chelates in which the central ketone interacts with two Lewis acids at the same time. As expected, treatment of 3-oxoglutarates and 4-oxopimelates with TiCl4 in a 1:1 ratio yielded unsymmetric single chelates in which the carbonyl groups of the ketone and one ester bind TiCl4, while the other ester remains free. Unfortunately, treatment of the same ketodiesters with TiCl4 in a 1:2 ratio did not produce the desired symmetric double chelates. Instead, 2:4 complexes were formed in which the free esters of the unsymmetric single chelates bind TiCl4 in the normal way, without assistance from the keto group. We attribute this observation to the inherent reluctance of ketones to bind multiple Lewis acids, as well as to unfavorable Cl · · ·Cl interactions created in the hypothetical double chelates by the simultaneous attachment of two octahedrally coordinated atoms of titanium to a single carbonyl oxygen atom.Key words: Lewis acids, chelation, ketodiesters, TiCl4.

Carbonyl catalysis enables a biomimetic asymmetric Mannich reaction

Science ◽  
2018 ◽  
Vol 360 (6396) ◽  
pp. 1438-1442 ◽  
Author(s):  
Jianfeng Chen ◽  
Xing Gong ◽  
Jianyu Li ◽  
Yingkun Li ◽  
Jiguo Ma ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
High Activity ◽  
Asymmetric Catalysis ◽  
Carbonyl Group ◽  
Mannich Reaction ◽  
Primary Amine ◽  
Chiral Amines ◽  
Carbonyl Groups ◽  
Diphenylphosphinyl Imines

Chiral amines are widely used as catalysts in asymmetric synthesis to activate carbonyl groups for α-functionalization. Carbonyl catalysis reverses that strategy by using a carbonyl group to activate a primary amine. Inspired by biological carbonyl catalysis, which is exemplified by reactions of pyridoxal-dependent enzymes, we developed an N-quaternized pyridoxal catalyst for the asymmetric Mannich reaction of glycinate with aryl N-diphenylphosphinyl imines. The catalyst exhibits high activity and stereoselectivity, likely enabled by enzyme-like cooperative bifunctional activation of the substrates. Our work demonstrates the catalytic utility of the pyridoxal moiety in asymmetric catalysis.

scholarly journals Frequency Doubled CO2 Laser Induced Decomposition of Carbonyl Compounds: Cyclobutanone

1984 ◽  
Vol 4 (1-6) ◽  
pp. 275-285 ◽  
Author(s):  
Mei-Kuen Au ◽  
P. A. Hackett ◽  
M. Humphries ◽  
P. John
Keyword(s):  
Carbonyl Compounds ◽  
Carbon Dioxide Laser ◽  
Second Harmonic ◽  
Multiphoton Absorption ◽  
Carbonyl Groups ◽  
Cyclic Ketones ◽  
Acyl Chlorides ◽  
Frequency Coverage ◽  
Product Array ◽  
Induced Decomposition

This paper reports the first use of radiation derived from a TEA carbon dioxide laser by nonlinear upshifting techniques (second harmonic generation) in initiating multiphoton absorption and dissociation. The frequency doubled CO2 laser has frequency coverage from 2180–1750 cm–1. This frequency region is of importance as it allows pumping of the fundamental stretching modes of organic carbonyl groups (anhydrides, acyl chlorides and strained cyclic ketones), inorganic carbonyl groups, and carbontritium bonds. The laser has been used to excite cyclobutanone in the region of the carbonyl stretch. Efficient multiphoton absorption and two channel dissociation are observed. The product array is consistent with that observed upon excitation at 10 μm.

Formation of Acetals and Ketals from Carbonyl Compounds: A New and Highly Efficient Method Inspired by Cationic Palladium

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1810-1814 ◽  
Author(s):  
Enoch A. Mensah ◽  
Shawn D. Green ◽  
Jesse West ◽  
Tyler Kindoll ◽  
Brenda Lazaro-Martinez
Keyword(s):  
Efficient Method ◽  
Palladium Catalyst ◽  
Carbonyl Compounds ◽  
Catalyst Loading ◽  
Carbonyl Groups ◽  
Simple Method ◽  
Ambient Temperatures ◽  
Highly Efficient ◽  
Low Catalyst Loading ◽  
Cationic Palladium

The development of a new, highly efficient, and simple method for masking carbonyl groups as acetals and ketals is described. This methodology relies on the nature of the palladium catalyst to direct the acetalization/ketalization reaction. This new protocol is mild and proceed with a very low catalyst loading at ambient temperatures. The method has been extended to a wide variety of different carbonyl compounds with various steric encumbrances to form the corresponding acetals and ketals in excellent yields.

scholarly journals Recent Advances in the Catalytic Synthesis of Imidazolidin-2-ones and Benzimidazolidin-2-ones

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 28 ◽  
Author(s):  
Alessandra Casnati ◽  
Elena Motti ◽  
Raffaella Mancuso ◽  
Bartolo Gabriele ◽  
Nicola Della Ca’
Keyword(s):  
Natural Products ◽  
Carbonyl Group ◽  
Ring Expansion ◽  
Catalytic Synthesis ◽  
Chiral Auxiliaries ◽  
Aziridine Ring ◽  
Urea Derivatives ◽  
Structural Motifs ◽  
Recent Advances ◽  
Direct Incorporation

2-Imidazolidinone and its analogues are omnipresent structural motifs of pharmaceuticals, natural products, chiral auxiliaries, and intermediates in organic syntheses. Over the years, continuous efforts have been addressed to the development of sustainable and more efficient protocols for the synthesis of these heterocycles. This review gives a summary of the catalytic strategies to access imidazolidin-2-ones and benzimidazolidin-2-ones that have appeared in the literature from 2010 to 2018. Particularly important contributions beyond the timespan will be mentioned. The review is organized in four main chapters that identify the most common approaches to imidazolidin-2-one derivatives: (1) the direct incorporation of the carbonyl group into 1,2-diamines, (2) the diamination of olefins, (3) the intramolecular hydroamination of linear urea derivatives and (4) aziridine ring expansion. Methods not included in this classification will be addressed in the miscellaneous section.

scholarly journals K2S2O8-promoted C–Se bond formation to construct α-phenylseleno carbonyl compounds and α,β-unsaturated carbonyl compounds

RSC Advances ◽  
2020 ◽  
Vol 10 (48) ◽  
pp. 28902-28905
Author(s):  
Xue-Yan Yang ◽  
Ruizhe Wang ◽  
Lu Wang ◽  
Jianjun Li ◽  
Shuai Mao ◽  
...  
Keyword(s):  
Carbonyl Group ◽  
Carbonyl Compounds ◽  
Bond Formation ◽  
Cross Coupling ◽  
Diphenyl Diselenide ◽  
Metal Free ◽  
The Cross

K2S2O8-promoted C–Se bond formation from the cross-coupling of C(sp3)–H bond adjacent to carbonyl group with diphenyl diselenide under metal-free conditions.

Infrared study of the interactions of acetone and siliceous surfaces

1969 ◽  
Vol 47 (14) ◽  
pp. 2545-2554 ◽  
Author(s):  
J. C. McManus ◽  
Yoshio Harano ◽  
M. J. D. Low
Keyword(s):  
Hydrogen Bonds ◽  
Carbonyl Group ◽  
Boron Atom ◽  
Porous Glass ◽  
Carbonyl Groups ◽  
Infrared Study ◽  
Oh Groups ◽  
Silica Surfaces ◽  
Surface Hydroxyls ◽  
Glass Surfaces

Adsorbed acetone is held to silica surfaces by hydrogen bonds between surface silanols and the acetone carbonyl groups. Acetone is adsorbed by this mechanism on porous glass surfaces but there is also some decomposition, as shown by the increase in surface B—OH groups and by formation of new C—H absorptions at 2984 and 2940 cm−1. Experiments with boron-impregnated silica indicated that the presence of boron in the porous glass can account for this decomposition process. Bands at 1660–1670 and 1650 cm−1, observed when acetone and acetone-d6, respectively, were adsorbed on either porous glass or boron-impregnated silica, are attributed to ν(C=O) of the carbonyl group coordinated with a surface boron atom. The surface hydroxyls of both silica and porous glass could exchange with the deuterium of acetone-d6 via a mechanism involving an enol intermediate.

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