?,?-Unsaturated Carbonyl Compounds with Sterically Protected Carbonyl Groups?Enforced a3versus a1 Reactivity

1979 ◽  
Vol 18 (12) ◽  
pp. 957-958 ◽  
Author(s):  
Dieter Seebach ◽  
Rita Locher
Keyword(s):  
Carbonyl Compounds ◽  
Carbonyl Groups

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.

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.

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.

Thermochemical studies of carbonyl compounds. 5. Enthalpies of reduction of carbonyl groups

1991 ◽  
Vol 113 (9) ◽  
pp. 3447-3450 ◽  
Author(s):  
Kenneth B. Wiberg ◽  
Louis S. Crocker ◽  
Kathleen M. Morgan
Keyword(s):  
Carbonyl Compounds ◽  
Carbonyl Groups

ChemInform Abstract: Thermochemical Studies of Carbonyl Compounds. Part 5. Enthalpies of Reduction of Carbonyl Groups.

ChemInform ◽  
2010 ◽  
Vol 22 (32) ◽  
pp. no-no
Author(s):  
K. B. WIBERG ◽  
L. S. CROCKER ◽  
K. M. MORGAN
Keyword(s):  
Carbonyl Compounds ◽  
Carbonyl Groups

scholarly journals STUDIES ON THE MODE OF ACTION OF LATHYROGENIC COMPOUNDS

1962 ◽  
Vol 116 (2) ◽  
pp. 119-130 ◽  
Author(s):  
C. I. Levene
Keyword(s):  
Guinea Pig ◽  
Carbonyl Compounds ◽  
Collagen Molecule ◽  
Cross Linking ◽  
Carbonyl Groups ◽  
Functional Sites ◽  
Reversal Effect ◽  
Chemical Combination ◽  
Simple Chemical

The lathyrogenic effect of INAH in the chick embryo may be measured by the increase in the extractibility of collagen from the bones with 1 M NaCl. Incubation of these bones in vitro with carbonyl compounds diminishes the amount of extractible collagen; with D-L-glyceraldehyde the reversal of the INAH effect is complete. This reversal effect is dependent on the time and temperature of incubation and on the quantity of D-L-glyceraldehyde, but is independent of the pH of the incubating medium, the optical form of the glyceraldehyde, or the metabolism of the cells; this suggests that it depends on a simple chemical combination. D-L-glyceraldehyde also reverses completely the extractibility of collagen from the bones of embryos rendered lathyrogenic with BAPN, semicarbazide, and hydrazine hydrate. The hypothesis has been advanced "that lathyrogenic agents act by blocking carbonyl groups on the collagen molecule, thus preventing cross-linking essential to normal maturation; normal maturation may be restored by the addition of carbonyl groups which act by competing either for the lathyrogen or for functional sites on the collagen molecule." In support of this hypothesis, it has been shown that purified lathyritic guinea pig collagen takes up lesser amounts of 2,4-dinitrophenylhydrazine—a compound which combines with carbonyl groups—than does normal collagen; it has been shown that lathyritic collagen still possesses the ability to form segment-long-spacing (SLS) collagen, but that these fibres are much thinner than normal; this is due perhaps to blockade of groups essential for lateral cross-linking of the tropocollagen unit. It has also been shown that normal, purified guinea pig collagen which has been pretreated with INAH, takes up lesser amounts of 2,4-dinitrophenylhydrazine and forms much thinner SLS fibres than the untreated controls.

Catalytic α-Hydroarylation of Acrylates and Acrylamides via an Interrupted Hydro-Dehalogenation Reaction

2020 ◽  
Author(s):  
Alena Vasquez ◽  
John Gurak ◽  
Candice Joe ◽  
Emily Cherney ◽  
Keary Engle
Keyword(s):  
Functional Groups ◽  
Carbonyl Compounds ◽  
High Selectivity ◽  
Mechanistic Study ◽  
Carbonyl Groups ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Optimized Conditions

The palladium-catalyzed, α-selective hydroarylation of acrylates and acrylamides is reported. Under optimized conditions, this method is highly tolerant of a wide range of substrates including those with base sensitive functional groups and/or multiple enolizable carbonyl groups. A detailed mechanistic study was undertaken, and the high selectivity of this transformation was shown to be enabled by the formation of an [Pd<sup>II</sup>(Ar)(H)] intermediate, which performs selective hydride insertion into the β-position of α,β-unsaturated carbonyl compounds. <br>

Transition-Metal- and Halogen-Free Oxidation of Benzylic sp3 C–H Bonds to Carbonyl Groups Using Potassium Persulfate

Synthesis ◽  
2017 ◽  
Vol 49 (17) ◽  
pp. 4007-4016 ◽  
Author(s):  
Yixin Hu ◽  
Lihong Zhou ◽  
Wenjun Lu
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Carbonyl Compounds ◽  
Potassium Persulfate ◽  
Benzoic Acids ◽  
Carbonyl Groups ◽  
Mild Conditions ◽  
Halogen Free ◽  
Free Oxidation

Aryl carbonyl compounds including acetophenones, benzophenones, imides, and benzoic acids are prepared from benzyl substrates using potassium persulfate as oxidant with catalytic pyridine in acetonitrile under mild conditions. Neither transition metals nor halogens are involved in the reactions.

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