3174-83-2Relevant academic research and scientific papers
Molecular behaviors of formaldehyde encapsulated in supercages of zeolite NaY with different loadings and its intrinsic reactivity for the carbonyl-ene reaction with α-methylstyrene
Sato, Kei-Ichi,Masui, Yoichi,Onaka, Makoto
, p. 1318 - 1324 (2017)
The reactivity of formaldehyde (HCHO) adsorbed in the supercages of zeolite NaY toward α-methylstyrene for the carbonyl-ene reaction was very dependent on the loading amount of HCHO in the NaY pores. We first prepared a series of NaY samples with different amounts of HCHO, and applied them to the carbonyl-ene reaction with excess amounts of α-methylstyrene to evaluate their intrinsic reactivities. It was found that one formaldehyde molecule adsorbed in one supercage of NaY produced 3-phenylbut-3-en-1-ol in the highest yield (83%), while for higher loading amounts of HCHO on NaY, lower yields of the product were obtained because the supercages were narrowed by the HCHO molecules as well as the homoallylic alcohol product and its over-reaction products. We next investigated their states of HCHO adsorbed in the pores by 13CDD/CPMASNMR analysis. When three HCHO molecules were adsorbed in a supercage, it was clarified that all the HCHO was exclusively encapsulated in a monomeric form, while most of the adsorbed HCHO with much higher loading amounts was transformed into 1,3,5-trioxane inside the supercages of NaY as well as paraformaldehyde outside the supercages.
Ni-Catalyzed Reductive Allylation of α-Chloroboronates to Access Homoallylic Boronates
Lou, Yixian,Qiu, Jian,Yang, Kai,Zhang, Feng,Wang, Chenglan,Song, Qiuling
supporting information, p. 4564 - 4569 (2021/06/28)
The transition-metal-catalyzed allylation reaction is an efficient strategy for the construction of new carbon-carbon bonds alongside allyl or homoallylic functionalization. Herein we describe a Ni-catalyzed reductive allylation of α-chloroboronates to efficiently render the corresponding homoallylic boronates, which could be readily converted into valuable homoallylic alcohols or amines or 1,4-diboronates. This reaction features a broad substrate scope with good functional group compatibility that is complementary to the existing methods for the preparation of homoallylic boronates.
Strong acid-catalyzed electrophilic ring expansion of oxetanes and sulfoxonium ylides
Xie, Wenlai,Xu, Jiaxi,Yuan, Wenhao
, (2021/06/28)
A strong protic acid-catalyzed electrophilic ring expansion of oxetanes into trans-2,3-disubstituted tetrahydrofuran derivatives using sulfoxonium ylides has been developed. This reaction produces functionalized trans-2,3-disubstituted tetrahydrofuran derivatives stereospecifically by using safe and stable sulfoxonium ylides without metal catalysts and the protection of inert gas.
Photo-induced oxidative cleavage of C-C double bonds of olefins in water
Zhang, Yilan,Yue, Xiaoguang,Liang, Chenfeng,Zhao, Jianming,Yu, Wenbo,Zhang, Pengfei
supporting information, (2021/08/27)
The carbonyl compounds, synthesized by the oxidative cleavage of their corresponding olefins, are of great significance in organic synthesis, especially aryl ketones. We have developed a gentle and effective protocol, using acid red 94 as the organic metal-free photocatalyst, O2 as the oxidant, and water as the solvent. Under visible light irradiation, aryl ketone derivatives were obtained in moderate to excellent yields, showing good economic and environmental advantages.
Base-Promoted C-C Bond Activation Enables Radical Allylation with Homoallylic Alcohols
Lübbesmeyer, Maximilian,Mackay, Emily G.,Raycroft, Mark A. R.,Elfert, Jonas,Pratt, Derek A.,Studer, Armido
supporting information, p. 2609 - 2616 (2020/03/03)
The Cα-Cβ bond in homoallylic alcohols can be activated under basic conditions, qualifying these nonstrained acyclic systems as radical allylation reagents. This reactivity is exemplified by photoinitiated (with visible light and/or
Carbamoyl Fluoride-Enabled Enantioselective Ni-Catalyzed Carbocarbamoylation of Unactivated Alkenes
Li, Yue,Luan, Yu-Xin,Qi, Shao-Long,Wang, Rong-Hua,Ye, Mengchun,Zhang, Feng-Ping
supporting information, p. 19844 - 19849 (2021/01/01)
A carbamoyl fluoride-enabled enantioselective Ni-catalyzed carbocarbamoylation of unactivated alkenes was developed, providing a broad range of chiral γ-lactams bearing an all-carbon quaternary center in 45-96% yield and 38-97% ee.
Catalytic Regioselective Isomerization of 2,2-Disubstituted Oxetanes to Homoallylic Alcohols
Cabré, Albert,Lledós, Agustí,Rafael, Sergi,Riera, Antoni,Sciortino, Giuseppe,Ujaque, Gregori,Verdaguer, Xavier
, p. 7521 - 7527 (2020/03/24)
The selective isomerization of strained heterocyclic compounds is an important tool in organic synthesis. An unprecedented regioselective isomerization of 2,2-disubstituted oxetanes into homoallylic alcohols is described. The use of tris(pentafluorophenyl
Rhodium-Catalyzed Diverse Arylation of 2,5-Dihydrofuran: Controllable Divergent Synthesis via Four Pathways
Dou, Xiaowei,Hayashi, Tamio,Lu, Tao,Xing, Junhao,Ye, Bihai,Zhu, Wanjiang
, p. 2958 - 2963 (2020/03/23)
The rhodium-catalyzed controllable diverse arylation of 2,5-dihydrofuran with arylboronic acids is reported. By fine-tuning of the reaction conditions, four different ring-opening or oxidative arylation pathways are controlled in the rhodium-catalyzed ary
Copper(I)-Catalyzed Enantioselective Intramolecular Aminotrifluoromethylation of O-Homoallyl Benzimidates
Mou, Xue-Qing,Rong, Feng-Ming,Zhang, Heng,Chen, Gong,He, Gang
supporting information, p. 4657 - 4661 (2019/06/17)
In the present paper, the Cu(I)-catalyzed intramolecular aminotrifluoromethylation of O-homoallyl benzimidates with Togni reagent I was reported. O-Homoallyl benzimidates equipped with terminal alkenes produced chiral 1,3-oxazines with high enantioselectivity in the presence of a chiral BOX ligand, and racemic tetrahydro-1,3-oxazepines were obtained in high yields from internal alkene derivatives with a monoprotected amino acid additive under similar conditions.
Photoredox-Catalyzed Cyclopropanation of 1,1-Disubstituted Alkenes via Radical-Polar Crossover Process
Luo, Wenping,Yang, Yi,Fang, Yewen,Zhang, Xinxin,Jin, Xiaoping,Zhao, Guicai,Zhang, Li,Li, Yan,Zhou, Wanli,Xia, Tingting,Chen, Bin
supporting information, p. 4215 - 4221 (2019/08/16)
The photoredox-neutral catalyzed cyclopropanation of 1,1-disubstituted alkenes via radical addition-anionic cyclization cascade has been successfully developed. Another new protocol based on photocatalytic allylation and cyclopropanation cascade was also described between allylic halide and halomethyl radical. In addition to the successful use of bis-catecholato silicates as the alkyl radical precursors, the acyl and alkyl radicals derived from 1,4-dihydropyridines were also engaged in this radical-polar crossover process. The competing experiments displayed that the 3-exo-tet mode of cyclization preferred over 4-exo and 5-exo cyclization modes, allowing for the selective 3-exo-tet cyclization. The superior nucleofuge character of bromide over chloride and tosylate has been demonstrated in the reaction of bromomethyl radical with homoallylic (pseudo)halides. This new protocol is characterized by its redox-neutral process, broad substrate scope, mild conditions, and good functional-group compatibility. (Figure presented.).
