COMMON SYNTHETIC SEQUENCES FOR OCHEM I
... take place in water as the medium, not in organic solvents like methylene chloride. Another difference is in the catalysis. In the vast majority of biological systems reactions are catalyzed by enzymes, which are organic macromolecules that have a high degree of specificity and precision. For exampl ...
... take place in water as the medium, not in organic solvents like methylene chloride. Another difference is in the catalysis. In the vast majority of biological systems reactions are catalyzed by enzymes, which are organic macromolecules that have a high degree of specificity and precision. For exampl ...
Asymmetric Organocatalysis
... One of these approaches consists in activating the acceptors – mostly α,β-unsaturated aldehydes (R4 = H) and ketones (R4 = alkyl) – by reversible conversion to a chiral iminium ion. As shown in Scheme 4.2a, reversible condensation of an α,β-unsaturated carbonyl compound with a chiral secondary ami ...
... One of these approaches consists in activating the acceptors – mostly α,β-unsaturated aldehydes (R4 = H) and ketones (R4 = alkyl) – by reversible conversion to a chiral iminium ion. As shown in Scheme 4.2a, reversible condensation of an α,β-unsaturated carbonyl compound with a chiral secondary ami ...
L-13
... the reaction and led to the production of allylated product 3a in 80% yield (entry 2).[6] Strong Lewis acids such as AlCl3 or BF3・OEt2 were not effective for the allylation (entries 3 and 4), probably because these catalysts are not stable under protic conditions. Sc(OTf)3 only gave a low yield of 3 ...
... the reaction and led to the production of allylated product 3a in 80% yield (entry 2).[6] Strong Lewis acids such as AlCl3 or BF3・OEt2 were not effective for the allylation (entries 3 and 4), probably because these catalysts are not stable under protic conditions. Sc(OTf)3 only gave a low yield of 3 ...
Lesmahagow High School CfE Advanced Higher Chemistry Unit 2
... The addition of water to an alkene is done in the presence of an acid catalyst. Again this process can produce more than one product. The more likely product of the reaction can be predicted by using Markovnikov’s rule. When water adds across an asymmetrical double bond the major product formed is t ...
... The addition of water to an alkene is done in the presence of an acid catalyst. Again this process can produce more than one product. The more likely product of the reaction can be predicted by using Markovnikov’s rule. When water adds across an asymmetrical double bond the major product formed is t ...
Stoichiometry Review Package Answer Key
... The following questions are based on the material covered so far. I will post full answers on my website (https://blogs.ubc.ca/rchatrath/) halfway through spring break to give you time to do the questions on your own. Please attempt the questions by yourself. You will not learn by copying. Stoichiom ...
... The following questions are based on the material covered so far. I will post full answers on my website (https://blogs.ubc.ca/rchatrath/) halfway through spring break to give you time to do the questions on your own. Please attempt the questions by yourself. You will not learn by copying. Stoichiom ...
Metal / σ-bond interactions
... for pathways involving a OA/RE sequence were higher than σ-CAM pathways. ...
... for pathways involving a OA/RE sequence were higher than σ-CAM pathways. ...
A Diels-Alder Synthesis
... instance, can form two different products. One in which the two ester substituents on the bicyclic frame are on the same side as the methylene bridge (exo product), the other in which they are on the opposite side (trans) of the bridge (endo product). Exo substituents are placed cis with respect to ...
... instance, can form two different products. One in which the two ester substituents on the bicyclic frame are on the same side as the methylene bridge (exo product), the other in which they are on the opposite side (trans) of the bridge (endo product). Exo substituents are placed cis with respect to ...
OS-FGI Lecture2
... VERY reactive! It can be generated by photolysing oxygen in the presence of a photosensitiser (usually a dye such as Rose Bengal). Singlet oxygen is nicely complementary to SeO2 in its allylic oxidations in that it forms allylic alcohols with migration of the double bond instead of retention of its ...
... VERY reactive! It can be generated by photolysing oxygen in the presence of a photosensitiser (usually a dye such as Rose Bengal). Singlet oxygen is nicely complementary to SeO2 in its allylic oxidations in that it forms allylic alcohols with migration of the double bond instead of retention of its ...
Reactions of Alcohols
... SN2 reaction between R-X and R-OWE NEED TO CONSIDER STERIC HINDERANCE. This might lead to E2! ...
... SN2 reaction between R-X and R-OWE NEED TO CONSIDER STERIC HINDERANCE. This might lead to E2! ...
Diels-Alder Reaction:
... In 1921, Otto Diels and Kurt Alder discovered that certain alkenes and alkynes can undergo a 1,4addition with conjugated dienes to give substituted cyclohexenes or 1,4-cyclohexadienes. In 1950, their work was recognized with a Nobel Prize in chemistry. The mechanism of the reaction involves a cyclic ...
... In 1921, Otto Diels and Kurt Alder discovered that certain alkenes and alkynes can undergo a 1,4addition with conjugated dienes to give substituted cyclohexenes or 1,4-cyclohexadienes. In 1950, their work was recognized with a Nobel Prize in chemistry. The mechanism of the reaction involves a cyclic ...
Mechanism of Aldol Condensation
... organic syntheses. Aldol condensations are also commonly discussed in university level organic chemistry classes as a good bond-forming reaction that demonstrates important reaction mechanisms.[In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hy ...
... organic syntheses. Aldol condensations are also commonly discussed in university level organic chemistry classes as a good bond-forming reaction that demonstrates important reaction mechanisms.[In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hy ...
PowerPoint **
... α-Elimination: Generation of Carbene Defination: A carbene is a divalent carbon species link to two adjacent groups by covalent bonds, possessing two nonbonded electrons and six valence electrons. Preparation of carbenes a. ...
... α-Elimination: Generation of Carbene Defination: A carbene is a divalent carbon species link to two adjacent groups by covalent bonds, possessing two nonbonded electrons and six valence electrons. Preparation of carbenes a. ...
Synthetic route to novel asymmetric tetradentate ligands
... design of the ligand is necessary. In this connection, unsymmetrical ligands are also required to imitate many of the active sites of the metalloproteins [4-6]. Tetradendate ONNO Schiff bases are well-known systems for coordination of metal ions, and their synthesis is easily accomplished by conden ...
... design of the ligand is necessary. In this connection, unsymmetrical ligands are also required to imitate many of the active sites of the metalloproteins [4-6]. Tetradendate ONNO Schiff bases are well-known systems for coordination of metal ions, and their synthesis is easily accomplished by conden ...
Nucleophilic Aromatic Substitution
... Attack of the strong nucleophile on the halogen substituted aromatic carbon forming an anionic intermediate. Loss of the leaving group, the halide ion restores the aromaticity. Kinetics of the reaction are observed to be second order. The addition step is the rate determining step (loss of aromatici ...
... Attack of the strong nucleophile on the halogen substituted aromatic carbon forming an anionic intermediate. Loss of the leaving group, the halide ion restores the aromaticity. Kinetics of the reaction are observed to be second order. The addition step is the rate determining step (loss of aromatici ...
name Page 1 of 6 Multiple Choice. Choose the best answer for the
... 10. An organic molecule has a molecular formula of C10H13N. Upon hydrogenation of this molecule with Pd/C, it reacts with 2 mol equivalents of H2. Hydrogenation with Lindlar's catalysts gives no reaction. Which of the following structures is constant with this information? (a) ...
... 10. An organic molecule has a molecular formula of C10H13N. Upon hydrogenation of this molecule with Pd/C, it reacts with 2 mol equivalents of H2. Hydrogenation with Lindlar's catalysts gives no reaction. Which of the following structures is constant with this information? (a) ...
Addition reactions
... bond the H (the E+) adds to the C with the most hydrogens & the X (the Nu:) adds to the most substituted carbon. - Vladimir V. Markovnikov, Russian, 1870 Substrate is an alkene & acts as the Nu: ...
... bond the H (the E+) adds to the C with the most hydrogens & the X (the Nu:) adds to the most substituted carbon. - Vladimir V. Markovnikov, Russian, 1870 Substrate is an alkene & acts as the Nu: ...
MS PowerPoint - Catalysis Eprints database
... I. V. Kozhevnikov, Russ. Chem. Rev. 56 (1987) 811 M. Misono, N. Mizuno, K. Katamura, A. Kasai, Y. Konishi, K. Sakata, T. Okuhara, Y. Yoneda, Bull. Chem. Soc. Jpn. 55 (1982) 400 ...
... I. V. Kozhevnikov, Russ. Chem. Rev. 56 (1987) 811 M. Misono, N. Mizuno, K. Katamura, A. Kasai, Y. Konishi, K. Sakata, T. Okuhara, Y. Yoneda, Bull. Chem. Soc. Jpn. 55 (1982) 400 ...
Chapter 20: Coordination Chemistry: Reactions of Complexes 131
... cases (b) and (c) because of higher values of the equilibrium constant. Suggest a reason why K 15 Is so different? The value of the stepwise formation constants drop from I to 4, as expected on statistical grounds. HO\\iever the fifth stepwise formation constant is substantially lower, suggesting a ...
... cases (b) and (c) because of higher values of the equilibrium constant. Suggest a reason why K 15 Is so different? The value of the stepwise formation constants drop from I to 4, as expected on statistical grounds. HO\\iever the fifth stepwise formation constant is substantially lower, suggesting a ...
Topic 8 Assessed Homework Task - A
... In a typical procedure, a mixture of 1.00 g of propanone, 5.00 g of ethane-1,2-diol and 0.100 g of benzenesulphonic acid, C6H5SO3H, is heated under reflux in an inert solvent. Benzenesulphonic acid is a strong acid. Which one of the following statements is not true? ...
... In a typical procedure, a mixture of 1.00 g of propanone, 5.00 g of ethane-1,2-diol and 0.100 g of benzenesulphonic acid, C6H5SO3H, is heated under reflux in an inert solvent. Benzenesulphonic acid is a strong acid. Which one of the following statements is not true? ...
(substituted) carbon
... The addition of water by electrophilic hydration follows Markovnikov’s rule, however carbocation rearrangements can occur because water is a poor nucleophile. The electrophilic hydration process is the reverse of the acidinduced elimination of water (dehydration) of alcohols previously ...
... The addition of water by electrophilic hydration follows Markovnikov’s rule, however carbocation rearrangements can occur because water is a poor nucleophile. The electrophilic hydration process is the reverse of the acidinduced elimination of water (dehydration) of alcohols previously ...
File
... Alex’s hypothesis was that the rate will be affected by changing the concentrations of the propanone and the iodine, as the reaction can happen without a catalyst. Hannah’s hypothesis was that as the catalyst is involved in the reaction, the concentrations of the propanone, iodine and the hydrogen i ...
... Alex’s hypothesis was that the rate will be affected by changing the concentrations of the propanone and the iodine, as the reaction can happen without a catalyst. Hannah’s hypothesis was that as the catalyst is involved in the reaction, the concentrations of the propanone, iodine and the hydrogen i ...
Stille reaction
The Stille reaction, or the Migita-Kosugi-Stille coupling, is a chemical reaction widely used in organic synthesis which involves the coupling of an organotin compound (also known as organostannanes) with a variety of organic electrophiles via palladium-catalyzed coupling reaction.The R1 group attached to the trialkyltin is normally sp2-hybridized, including alkenes, and aryl groups; however, conditions have been devised to incorporate both sp3-hybridized groups, such as allylic and benzylic substituents, and sp-hybridized alkynes. These organostannanes are also stable to both air and moisture, and many of these reagents are either commercially available or can be synthesized from literature precedent. However, these tin reagents tend to be highly toxic. X is typically a halide, such as Cl, Br, I, yet pseudohalides such as triflates and sulfonates and phosphates can also be used.The groundwork for the Stille reaction was laid by Colin Eaborn, Toshihiko Migita, and Masanori Kosugi in 1976 and 1977, who explored numerous palladium catalyzed couplings involving organotin reagents. John Stille and David Milstein developed a much milder and more broadly applicable procedure in 1978. Stille’s work on this area might have earned him a share of the 2010 Nobel Prize, which was awarded to Richard Heck, Ei-ichi Negishi, and Akira Suzuki for their work on the Heck, Negishi, and Suzuki coupling reactions. However, Stille died in the plane crash of United Airlines Flight 232 in 1989.Several reviews have been published on the Stille reaction.