Enantioselective Henry Reactions under Dual Lewis Acid/Amine
... Claudio Palomo,* Mikel Oiarbide, and Antonio Laso There is increasing interest in developing catalytic asymmetric C C bond-forming processes.[1] In this endeavor the Henry reaction[2] is prominent because of the versatile chemistry of the nitro group.[3] Remarkably, however, while this reaction is c ...
... Claudio Palomo,* Mikel Oiarbide, and Antonio Laso There is increasing interest in developing catalytic asymmetric C C bond-forming processes.[1] In this endeavor the Henry reaction[2] is prominent because of the versatile chemistry of the nitro group.[3] Remarkably, however, while this reaction is c ...
- Cypress HS
... to react, in the reverse direction to the original process. As the concentration of products begins to build up, product molecules will react more and more frequently. Eventually, as the speed of the forward reaction decreases while the speed of the reverse reaction increases, the forward and revers ...
... to react, in the reverse direction to the original process. As the concentration of products begins to build up, product molecules will react more and more frequently. Eventually, as the speed of the forward reaction decreases while the speed of the reverse reaction increases, the forward and revers ...
Mechanisms of Alkenes
... – Attack by pi bond on polarized X-X with Halonium Ion formation – Attack by H2O to pop open threemembered ring. – Removal of extra proton (H+) by X- to complete the formation of –OH. ...
... – Attack by pi bond on polarized X-X with Halonium Ion formation – Attack by H2O to pop open threemembered ring. – Removal of extra proton (H+) by X- to complete the formation of –OH. ...
Applications of N-Heterocyclic Carbenes in Organic Reactions
... NHC ligands is the recent advance. Ø Although NHCs can be considered as phosphane mimics it has become apparent that there are substantial differences between the two ligand families. Ø Many of these carbene species show high catalytic activity in many metal-mediated organic transformations, e.g. ru ...
... NHC ligands is the recent advance. Ø Although NHCs can be considered as phosphane mimics it has become apparent that there are substantial differences between the two ligand families. Ø Many of these carbene species show high catalytic activity in many metal-mediated organic transformations, e.g. ru ...
Azetidinone : A bioactive moiety
... Desai, N.C ,Dave, D.,Shah M.D. and Vyas G.D , Synthesis and antibacterial activity of some novel 4 oxo- 1,3 thiazolidines, 2 oxo azetidines and 5 oxoimidazolines, Part vi, Indian Journal of Chemistry, Vol 39B, April 2000 ,277-282 Mehta P.D., Sengar N.P.S. ,Subramaniyam E.V.S. and Satyanarayana D.,Sy ...
... Desai, N.C ,Dave, D.,Shah M.D. and Vyas G.D , Synthesis and antibacterial activity of some novel 4 oxo- 1,3 thiazolidines, 2 oxo azetidines and 5 oxoimidazolines, Part vi, Indian Journal of Chemistry, Vol 39B, April 2000 ,277-282 Mehta P.D., Sengar N.P.S. ,Subramaniyam E.V.S. and Satyanarayana D.,Sy ...
Reaction of orthoesters with alcohols in the presence of acidic
... also. As O-acetylation with orthoester is not hitherto a known reaction, we were curious to explore this to find out whether such a transformation could be useful as a synthetic methodology and the results are summarized in Table I. Thus the reaction of alcohols and orthoester with various acid cata ...
... also. As O-acetylation with orthoester is not hitherto a known reaction, we were curious to explore this to find out whether such a transformation could be useful as a synthetic methodology and the results are summarized in Table I. Thus the reaction of alcohols and orthoester with various acid cata ...
Notes 07 Organometallic Compounds with notes
... Which (if any) of the following would not be classified as an organometallic substance? A) triethylaluminum B) ethylmagnesium bromide C) potassium tert-butoxide D) none of these (all are organometallic compounds) ...
... Which (if any) of the following would not be classified as an organometallic substance? A) triethylaluminum B) ethylmagnesium bromide C) potassium tert-butoxide D) none of these (all are organometallic compounds) ...
File
... number of protons adjacent to a given proton iii. the effect of radio waves on proton spin in nmr, limited to 1H nuclei iv. the use of magnetic resonance imaging as a noninvasive technique, eg scanning for brain disorders, or the use of nmr to check the purity of a compound in the pharmaceutical ind ...
... number of protons adjacent to a given proton iii. the effect of radio waves on proton spin in nmr, limited to 1H nuclei iv. the use of magnetic resonance imaging as a noninvasive technique, eg scanning for brain disorders, or the use of nmr to check the purity of a compound in the pharmaceutical ind ...
answer
... The tropane alkaloid (–)-hyoscyamine is found in certain plants of the Solanaceae family. It is an anticholinergic agent that works by blocking the action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands and the ...
... The tropane alkaloid (–)-hyoscyamine is found in certain plants of the Solanaceae family. It is an anticholinergic agent that works by blocking the action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands and the ...
Alcohols, Ethers, and Epoxides
... • Must convert the hydroxyl group (in alcohols) or the alkoxy group (in ethers) into a good leaving group before substitution or elimination will occur • Epoxides are strained three‐membered cyclic ethers that are very reactive towards strong nucleophiles and acids due t ...
... • Must convert the hydroxyl group (in alcohols) or the alkoxy group (in ethers) into a good leaving group before substitution or elimination will occur • Epoxides are strained three‐membered cyclic ethers that are very reactive towards strong nucleophiles and acids due t ...
Selective synthesis of cyclododec-2-en-1
... methoxyethanol, in 6 h, relatively good conversion (73.4%) and selectivity (85%) towards the isomeric (2methoxyethoxy)cyclododec-2-ene were achieved (Figures 2 and 3, Run No. 3). Similar results were obtained with 2-ethoxyethanol as reagent. Further increases in the reaction duration did not affect ...
... methoxyethanol, in 6 h, relatively good conversion (73.4%) and selectivity (85%) towards the isomeric (2methoxyethoxy)cyclododec-2-ene were achieved (Figures 2 and 3, Run No. 3). Similar results were obtained with 2-ethoxyethanol as reagent. Further increases in the reaction duration did not affect ...
Addition of Alcohols to Form Hemiacetals and Acetals
... Ammonia and primary amines form imines. Amines and aldehydes or ketones react to form hemiaminals, the nitrogen analogs of hemiacetals. The hemiaminals of primary amines then lose water to form an imine (previously, Schiff base). This is the nitrogen analog of the carbonyl group. ...
... Ammonia and primary amines form imines. Amines and aldehydes or ketones react to form hemiaminals, the nitrogen analogs of hemiacetals. The hemiaminals of primary amines then lose water to form an imine (previously, Schiff base). This is the nitrogen analog of the carbonyl group. ...
Journal of Physical and Chemical Reference Data
... all the possible heats of reaction. To get around this problem we define for each substance a standard reaction and tabulate its associated heat of reaction. These reactions and their associated heats of reaction can then be used to calculate the heats of other reactions. This standard reaction is k ...
... all the possible heats of reaction. To get around this problem we define for each substance a standard reaction and tabulate its associated heat of reaction. These reactions and their associated heats of reaction can then be used to calculate the heats of other reactions. This standard reaction is k ...
Reaction Rate Reading Packet
... For the same mass, many small particles have a greater total surface area than one large particle. For example, steel wool has a larger surface area than a block of steel of the same mass. This allows oxygen molecules to collide with many more iron atoms per unit of time. The more surface contact be ...
... For the same mass, many small particles have a greater total surface area than one large particle. For example, steel wool has a larger surface area than a block of steel of the same mass. This allows oxygen molecules to collide with many more iron atoms per unit of time. The more surface contact be ...
Ring-closing metathesis
Ring-closing metathesis, or RCM, is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the E- or Z- isomers and volatile ethylene.The most commonly synthesized ring sizes are between 5-7 atoms; however, reported syntheses include 45- up to 90- membered macroheterocycles. These reactions are metal-catalyzed and proceed through a metallacyclobutane intermediate. It was first published by Dider Villemin in 1980 describing the synthesis of an Exaltolide precursor, and later become popularized by Robert H. Grubbs and Richard R. Schrock, who shared the Nobel Prize in Chemistry, along with Yves Chauvin, in 2005 for their combined work in olefin metathesis. RCM is a favorite among organic chemists due to its synthetic utility in the formation of rings, which were previously difficult to access efficiently, and broad substrate scope. Since the only major by-product is ethylene, these reactions may also be considered atom economic, an increasingly important concern in the development of green chemistry.There are several reviews published on ring-closing metathesis.