72055-87-9Relevant academic research and scientific papers
Reductive Alkylation of Alkenyl Acetates with Alkyl Bromides by Nickel Catalysis
Bai, Yunfei,Han, Guan-Yu,He, Rong-De,Liu, Xue-Yuan,Pan, Xiaobo,Pang, Xiaobo,Shu, Xing-Zhong,Zhao, Zhen-Zhen
supporting information, (2021/12/14)
Catalytic alkylation of stable alkenyl C?O electrophiles is synthetically appealing, but studies to date have typically focused on the reactions with alkyl Grignard reagents. We report herein a cross-electrophile reaction of alkenyl acetates with alkyl bromides. This work has enabled a new method for the synthesis of aliphatic alkenes from alkenyl acetates to be established that can be used to add more structural complexity and molecular diversity with enhanced functionality tolerance. The method allows for a gram-scale reaction and modification of biologically active molecules, and it affords access to useful building blocks. Preliminary mechanistic studies reveal that the NiI species plays an essential role for the success of the coupling of these two reactivity-mismatched electrophiles.
Intramolecular [2+2] Photocycloaddition of Cyclic Enones: Selectivity Control by Lewis Acids and Mechanistic Implications
Poplata, Saner,Bauer, Andreas,Storch, Golo,Bach, Thorsten
, p. 8135 - 8148 (2019/05/29)
The intramolecular [2+2] photocycloaddition of 3-alkenyl-2-cycloalkenones was performed in an enantioselective fashion (nine representative examples, 54–86 % yield, 76–96 % ee) upon irradiation at λ=366 nm in the presence of an AlBr3-activated oxazaborolidine as the Lewis acid. An extensive screening of proline-derived oxazaborolidines showed that the enantioface differentiation depends strongly on the nature of the aryl group at the 3-position of the heterocycle. DFT calculations of the Lewis acid–substrate complex indicate that attractive dispersion forces may be responsible for a change of the binding mode. The catalytic [2+2] photocycloaddition was shown to proceed on the triplet hypersurface with a quantum yield of 0.05. The positive effect of Lewis acids on the outcome of a given intramolecular [2+2] photocycloaddition was illustrated by optimizing the key step in a concise total synthesis of the sesquiterpene (±)-italicene.
A Multistep Rearrangement from 2,2-Disubstituted 1,3-Cyclohexanediones to 3-Substituted 2-Cyclohexenones via Phosphonate Anions and Its Application to a Formal Synthesis of (+/-)-α-Acoradiene
Yamamoto, Yoshinori,Furuta, Toshiaki
, p. 3971 - 3972 (2007/10/02)
The reaction of 2,2-disubstituted 1,3-cyclohexanediones (1) with dimethyl methylphosphonate anion in the presence of trimethylsilyl chloride produces 3-substituted 2-cyclohexenones (2) in moderate to very good yields.This new overall reaction is accounted for by (a) attack of the phosphonate anion on a carbonyl group, (b) retro-aldol cleavage, (c) reorganization of the acidic proton, and (d) an intramolecular Wadsworth-Emmonds condensation.The new rearrangement is applied to a short synthesis of (+/-)-α-acoradiene.
45. Total Synthesis of (+/-)-α-Acoradiene via Intramolecular Photoaddition and Reductive Cyclobutane Cleavage
Oppolzer, Wolfgang,Zutterman, Freddy,Baettig, Kurt
, p. 522 - 533 (2007/10/02)
(+/-)-α-Acoradiene (4) has been synthesized from 3-methoxy-2-cyclohexenone by a sequence of 8 steps.The key steps (Scheme 6) are the regio- and stereoselective photoaddition 7 -> 6 and the reductive fragmentation 6 -> 5.
Intramolecular Photochemical Cycloaddition Reactions of 3-(1,5-Dimethylhex-4-enyl)cyclohex-2-enone: Regio- and Stereochemical Aspects
Hoye, Thomas R.,Martin, Steven J.,Peck, David R.
, p. 331 - 337 (2007/10/02)
The intramolecular photocycloaddition reaction of the title enone (1) and its 1-demethyl analogue (2) gives head-to-head , adducts containing cyclopentacyclobutabenzen-5(6H)-one skeletons and none of the head-to-tail isomers of the tricycl
