1868-00-4Relevant articles and documents
Photo-induced phosphorus radical involved semipinacol rearrangement reaction: Highly synthesis of γ-oxo-phosphonates
Wang, Chunhai,Huang, Xiaoling,Liu, Xueting,Gao, Suqian,Zhao, Bin,Yang, Shangdong
supporting information, p. 677 - 680 (2019/08/27)
Hydroxyphosphoric acids display the unique biological activities, and they have some attractive prospects as clinical drug moleculars. Herein, a new approach for the synthesis of γ-oxo-phosphonates (the precursor of hydroxyphosphoric acid) has been established through the semipinacol rearrangement tactic involved the photo-induced phosphorus radical process. Most important, this transformation is avoid of the external oxidants, and occurs very well under the sunlight irradiation, meanwhile the γ-oxo-phosphonate was easily derivatized to obtain γ-hydroxyphosphoric acid, thus highlights the synthesis value of this method.
Synthesis of Symmetrical Diaryl Ketones by Cobalt-Catalyzed Reaction of Arylzinc Reagents with Ethyl Chloroformate
Rérat, Alice,Michon, Christophe,Agbossou-Niedercorn, Francine,Gosmini, Corinne
, p. 4554 - 4560 (2016/09/23)
Symmetrical diaryl ketones were prepared by a cross-coupling reaction between aryl bromides and ethyl chloroformate. This new method, which uses a catalyst composed of CoBr2and a bipyridine ligand along with readily available starting materials, allows for the synthesis of a variety of symmetrical diaryl ketones in moderate to excellent yields (37–99 %) under mild conditions. This reaction, in which ethyl chloroformate acts as a surrogate of carbon monoxide in the presence of cobalt and zinc, represents an interesting alternative to previously known approaches for the synthesis of diarylmethanones.
Oxalyl chloride as carbonyl synthon in Pd-catalyzed carbonylations of triarylbismuth and triarylindium organometallic nucleophiles
Rao, Maddali L. N.,Venkatesh, Varadhachari,Dasgupta, Priyabrata
supporting information; experimental part, p. 4975 - 4980 (2011/01/12)
Oxalyl chloride has been demonstrated to function as C1 carbonyl synthon in the carbonylations of triarylbismuth and triarylindium nucleophiles under palladium-catalyzed conditions. All the three aryl groups from both bismuth and indium reagents participated in carbonylative couplings to afford the corresponding functionalized ketones in high yields. This study also disclosed a novel utilization of oxalyl chloride as facile alternative source of CO for carbonylations under palladium catalysis.
Isomerization and 1,3-dipolar cycloaddition of gem-difluorinated NH-azomethine ylides in the reaction of difluorocarbene with diarylmethanimines
Novikov,Khlebnikov,Khistyaev,Magull
experimental part, p. 1070 - 1079 (2009/08/08)
Reaction of difluorocarbene with diarylmethanimines leads to the formation of gem-difluorinated NH-azomethine ylides, two types of competing transformations of which are found to be characteristic: a formal 1,2-H shift into N-(difluoromethyl)imines and 1,3-dipolar cycloaddition to electron-deficient multiple bonds. α,α,α-Trifluoroaceto- phenones are efficient dipolar traps for difluoro NH-ylides, the addition of which to the dipole proceeds regioselectively with the formation of 4-fluoro-2,5-dihydrooxazoles. According to the quantum-chemical calculations by the DFT B3LYP/6-31G*method, 1,3-dipolar cycloaddition of difluorinated NH-azomethine ylides to a C=O bond with the formation of 4-fluoro derivatives of oxazole has lower barrier of activation than the reaction, leading to another regioisomer; the formal 1,2-H shift in the ylide occurs intermolecularly with participation of an imine, a precursor of the ylide.
Dications of fluorenylidenes. The relationship between redox potentials and antiaromaticity for meta- and para-substituted diphenylmethylidenefluorenes
Mills, Nancy S.,Tirla, Cornelia,Benish, Michele A.,Rakowitz, Amber J.,Bebell, Lisa M.,Hurd, Caroline M. M.,Bria, Anna L. M.
, p. 10709 - 10716 (2007/10/03)
Electrochemical oxidation of meta-substituted diphenylmethylidenefluorenes (3a-g) results in the formation of fluorenylidene dications that are shown to be antiaromatic through calculation of the nucleus independent chemical shift (NICS) for the 5- and 6-
Kinetics and Mechanism of the Methyltrioxorhenium-Catalyzed Sulfoxidation of Thioketones and Sulfines
Huang, Ruili,Espenson, James H.
, p. 6374 - 6376 (2007/10/03)
Kinetic studies have been carried out on the oxidation of thiobenzophenones and thiocamphor by hydrogen peroxide and on the second step in the sequence, oxidation of the resulting sulfines (Ar2C= S=O). The first reaction follows the pattern now common to methyltrioxorhenium/H2O2 reactions, in that the rate constant for the reaction between the peroxorhenium intermediate and the thioketone follows a Hammett correlation such that electron-releasing substrates react more rapidly. The reaction constant is p = -1.12. However, the plot of log(kX/kH) for the sulfines against 2σ, determined over the range -1.6 2 under these conditions rather than undergoing disproportionation to SO2 and S. Also, SO was trapped with a 1,3-diene as a thiophene-1-oxide.
N-CARBOETHOXYPIPERIDINE, A CONVENIENT REAGENT FOR THE PREPARATION OF SYMMETRICAL KETONES FROM ORGANOLITHIUMS
Prakash, G. K. Surya,York, Chentao,Liao, Qimu,Kotian, Kirtivan,Olah, George A.
, p. 79 - 84 (2007/10/02)
N-Carboethoxypiperidine on reaction with organolithium reagents, RLi, followed by acidic work-up gave excellent yields of the corresponding symmetrical ketones, R2CO.
Pentadieneamides
-
, (2008/06/13)
Compounds of the formula STR1 Y is O ir S, *A is paraphenylene or *----(CH2)n----(X)m --(CH2)r ----, X is O, S or --CH=CH--, n or r, independently, are integers from 0 to 3, s is an integer from 0 to 1, m is an integer from 0 to 1, provided that when m is 1, n+s must be at least 2, R1 and R2, independently, are hydrogen, lower alkyl, cycloalkyl, lower alkenyl, Het, aryl, R3, R4 and R8, independently, are hydrogen, lower alkyl, aryl, R5 and R6, independently, are hydrogen or lower alkyl, R7 is hydrogen, lower alkyl, cycloalkyl, Het-lower alkyl or aryl, Het is a monocyclic 5- or 6-membered hetero aromatic or a bicyclic heteroaromatic radical containing one or two hetero atoms selected from nitrogen, oxygen and sulfur, which radical may be substituted by lower alkyl, halogen or aryl, and the asterisk denotes the point of attachment, and when R6 and R7 are different, their enantiomers and racemic mixtures thereof, when R1 and R2 are different, their geometric isomers, and pharmaceutically acceptable acid addition salts thereof, are described. The compounds of formula I exhibit activity as platelet activating factor (PAF) antagonists and are, therefore, useful in disease states characerized by excess platelet activating factor or for the prevention and treatment of cardiovascular disease, pulmonary diseases, immunological disorders, inflammatory diseases, dermatological disorders, shock or transplant rejection.
Benzophenones and benzhydrols
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, (2008/06/13)
Compounds having the formula STR1 WHERE X is --CO-- or --CHOH--, Y and Z are halogen, alkyl, trifluoromethyl, alkoxy, hydroxy, nitro, cyano, carboxy, carbalkoxy, carbamoyl, or alkylthio, and m and n are 0, 1, or 2 Are useful in controlling undesirable secondary growth in plants, particularly sucker growth in tobacco.