19396-83-9Relevant academic research and scientific papers
On the Reaction of (Dibromomethyl)lithium with Bicyclic and Tricyclic Ketones
Teager, David S.,Ward, Harry D.,Murray, Roger K.
, p. 5493 - 5499 (1993)
Many literature examples show that the reaction of a simple cyclic ketone with (dibromomethyl)lithium at -78 deg C, followed by low-temperature hydrolysis of the resulting lithium alkoxide 33, gives the corresponding dibromomethyl alcohol.We have found that the reaction of a bicyclic or tricyclic ketone with (dibromomethyl)lithium under comparable conditions provides a dibromomethyl alcohol and/or an α-bromo aldehyde.The latter product appears to result from an intramolecular displacement reaction in 33 to give a bromo epoxide, which then rearranges stereospecifically to the α-bromo aldehyde.The product ratios obtained in all of these reactions seem to be determined by the steric interactions in 33 between the alkoxide and dibromomethyl groups and the hydrogens that are syn to them at the carbons which are β to the original carbonyl carbon.As these steric interactions increase, the proportion of α-bromo aldehyde in the product mixture increases.If 33 obtained from any cyclic ketone is warmed to 10 deg C before it is hydrolyzed, then the only product isolated is the α-bromo aldehyde.
Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
Chen, Junjun,Hua, Kaimin,Liu, Xiaofang,Deng, Yuchao,Wei, Baiyin,Wang, Hui,Sun, Yuhan
, p. 9919 - 9924 (2021/05/31)
Performing carbonylation without the use of carbon monoxide for high-value-added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear-selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
Method for preparing aldehyde through hydroformylation of internal olefin
-
Paragraph 0041-0042, (2020/04/29)
The invention provides a method for preparing aldehyde through hydroformylation of internal olefin. The preparation method is characterized by comprising the following steps: adding a water-soluble rhodium compound, a water-soluble diphosphine ligand, an additive, deionized water and internal olefin into a reaction kettle equipped with a stirrer and a thermocouple; carrying out replacing 3-5 timesby using synthesis gas formed by mixing hydrogen and carbon monoxide according to a volume ratio of 1: 1; carrying out pressurizing to 1.0-5.0 MPa; conducting a reaction for 2-10 hours at a temperature of 60-120 DEG C; and conducting cooling, taking out a reaction product, and performing separating to obtain the product aldehyde.
NOVEL 5 OR 8-SUBSTITUTED IMIDAZO [1, 5-a] PYRIDINES AS INDOLEAMINE AND/OR TRYPTOPHANE 2, 3-DIOXYGENASES
-
Paragraph 0492, (2016/10/31)
Disclosed herein are 5 or 8-substituted imidazo[l,5-a]pyridines and pharmaceutical compositions comprising at least one such 5 or 8-substituted imidazo[l,5-a]pyridines, processes for the preparation thereof, and the use thereof in therapy. Disclosed herein are certain 5 or 8- substituted imidazo[l,5-a]pyridines that can be useful for inhibiting indoleamine 2,3- dioxygenase and/or tryptophane 2,3-dioxygenase and for treating diseases or disorders mediated thereby.
Ruthenium Catalyzed Selective α- And α,β-Deuteration of Alcohols Using D2O
Chatterjee, Basujit,Gunanathan, Chidambaram
supporting information, p. 4794 - 4797 (2015/10/12)
Highly selective ruthenium catalyzed α-deuteration of primary alcohols and α,β-deuteration of secondary alcohols are achieved using deuterium oxide (D2O) as a source of deuterium and reaction solvent. Minimal loading of catalyst (Ru-macho), base (KOtBu), and low temperature heating provided efficient selective deuteration of alcohols making the process practically attractive and environmentally benign. Mechanistic studies indicate the D-O(D/R) bond activations by metal-ligand cooperation and intermediacy of carbonyl compounds resulting from dehydrogenation of alcohols.
Practical large-scale preparation of (±)-2-exo-norbornyl carboxylic acid and its improved isolation as the sodium salt
Gu, Jianxin,Storz, Thomas,Vyverberg, Frederick,Wu, Charles,Varsolona, Richard J.,Sutherland, Karen
experimental part, p. 942 - 945 (2012/07/14)
A practical, robust, and high-yielding three-step-one-pot procedure for the diastereoselective synthesis of (±)-2-exo-norbornyl carboxylic acid starting from norbornylene has been found and demonstrated on multikilogram scale, setting a new benchmark for
New methods of hydroformylation of olefins and isomerisation of allyl alcohols using the CoBr2/Zn/CO/t-BuOH reagent system
Rajesh,Periasamy
, p. 989 - 993 (2007/10/03)
The reaction of CoBr2/Zn/CO/t-BuOH gives cobalt carbonyl species that is useful for the hydroformylation of olefins to obtain corresponding aldehydes. The cobalt carbonyl species formed is also useful in isomerisation of allyl alcohols to the corresponding ketones.
Oxoammonium resins as metal-free, highly reactive, versatile polymeric oxidation reagents
Weik, Steffen,Nicholson, Graeme,Jung, Gnther,Rademann, Jrg
, p. 1436 - 1439 (2007/10/03)
Polymer-supported oxidation of alcohols was conducted very efficiently by employing oxoammonium salts, the reactive intermediates in TEMPO oxidations (TEMPO = 2,2,6,6-tetramethylpiperidinoxyl). These highly reactive salts (see scheme; X = Br, C1) could be prepared and isolated on the polymeric support, and were used for the conversion of single compounds as well as of complex mixtures of alcohols.
Kinetics and mechanism of acid-catalyzed hydration of 5-hydroxymethyl- and 5-phenoxymethylnorborn-2-enes
Lajunen, Martti,Latva-Nirva, Esa
, p. 719 - 723 (2007/10/03)
The disappearance rate constants for exo- and endo-5-hydroxymethylnorborn-2-enes (3 and 4) and exo- and endo-5-phenoxymethylnorborn-2-enes (5 and 6) were measured in aqueous perchloric acid by a capillary GC method at different temperatures and acid concentrations. The rate constants, activation parameters, excess acidity plots and products (for 3 and 4 only) are in agreement with the rate-determining protonation of the double bond (AdE2 mechanism). No proof of endo protonation of the double bond via the protonated endo-5-CH2OH group was obtained. The excess acidity plots were corrected according to the partial protonation of the hydroxylic or ether oxygen atom. In the case of 3 and 4, the slope parameter m?, indicative of the transition state, decreases slightly with increasing temperature, the intercept parameter log (ko/M-1s-1) depends reasonably on the temperature, and the protonation site parameters of the hydroxymethyl group, m′ and pKS′H+, are temperature-independent. The corresponding parameters for 5 and 6 at 303 K are normal except the peculiar pKS′H+ values, ca. -2.5.
Organic Oxoammonium Salts. 3. A New Convenient Method for the Oxidation of Alcohols to Aldehydes and Ketones
Ma, Zhenkun,Bobbitt, James M.
, p. 6110 - 6114 (2007/10/02)
A new method for the selective oxidation of alcohols using organic oxoammonium salts generated by acid-promoted disproportionation of nitroxides in solution has been developed.Major advantages are high yields, ease of product isolation, and a high degree of selectivity in the presence of other functional groups.
