89619-03-4Relevant articles and documents
Trichloromethylative Olefin Cycloamination by Photoredox Catalysis
Harada, Shinji,Masuda, Ryuya,Morikawa, Takahiro,Nishida, Atsushi
supporting information, p. 4531 - 4535 (2021/08/30)
The trichloromethyl group is an important functionality. It is a useful synthetic moiety and appears in the structures of natural and biologically active compounds; hence, developing synthetic methods for its introduction into structural motifs is an important objective. Herein, we report an efficient chemistry for the trichloromethylations and cycloaminations of olefin. These reactions are realized in a single step and triggered by the addition of the trichloromethyl radical, generated from bromotrichloromethane by photoredox catalysis, to a double bond, with the resulting intermediate trapped through intramolecular reaction with an amino group. This process facilitates the construction of N-heterocycles having trichloromethyl units and tetrasubstituted carbons from simple compounds under mild conditions.
Copper-Catalyzed Enantiotopic-Group-Selective Allylation of gem-Diborylalkanes
Kim, Minjae,Park, Bohyun,Shin, Minkyeong,Kim, Suyeon,Kim, Junghoon,Baik, Mu-Hyun,Cho, Seung Hwan
supporting information, p. 1069 - 1077 (2021/01/25)
We report a copper-catalyzed enatiotopic-group-selective allylation of gem-diborylalkanes with allyl bromides. The combination of copper(I) bromide and H8-BINOL derived phosphoramidite ligand proved to be the most effective catalytic system to provide various enantioenriched homoallylic boronate esters, containing a boron-substituted stereogenic center that is solely derived from gem-diborylalkanes, in good yields with high enantiomeric ratios under mild conditions. Experimental and theoretical studies have been conducted to elucidate the reaction mechanism, revealing how the enatiotopic-group-selective transmetalation of gem-diborylalkanes with chiral copper complex occurs to generate chiral α-borylalkyl-copper species for the first time. Additional synthetic applications to the synthesis of various chiral building blocks are also included.
Asymmetric Reductive and Alkynylative Heck Bicyclization of Enynes to Access Conformationally Restricted Aza[3.1.0]bicycles
Chi, Yonggui Robin,Huang, Xiaolei,Nguyen, Minh Hieu,Pu, Maoping,Wu, Yun-Dong,Zhang, Luoqiang,Zhou, Jianrong Steve
supporting information, p. 10814 - 10818 (2020/06/09)
Conformationally restricted azabicycles are becoming increasingly important in medicinal research. Asymmetric Heck bicyclization of enynes proceeds to give medicinally useful aza[3.1.0] and aza[4.1.0] bicycles with excellent enantioselectivity. The key organopalladium species after bicyclization can be trapped by silanes and terminal alkynes.
Enantioselective Synthesis of 4-Allyl Tetrahydroquinolines via Copper(I) Hydride-Catalyzed Hydroallylation of 1,2-Dihydroquinolines
Xu-Xu, Qing-Feng,You, Shu-Li,Zhang, Xiao
supporting information, p. 1530 - 1534 (2020/03/13)
CuCl/(R,R)-Ph-BPE-catalyzed asymmetric hydroallylation of 1,2-dihydroquinolines, prepared from readily available quinolines, was developed. The optically active tetrahydroquinolines (THQs) bearing an allylic functionality at position 4 were obtained in good yields and excellent enantioselectivity. The introduced allylic groups are amenable to diverse transformations, thus offering chances to rapidly expand the THQ libraries.
Palladium-Catalyzed Spirocyclization through C?H Activation and Regioselective Alkyne Insertion
Yoon, Hyung,R?lz, Martin,Landau, Felicitas,Lautens, Mark
supporting information, p. 10920 - 10923 (2017/08/30)
A Pd-catalyzed spirocyclization involving a sequential carbopalladation, intramolecular C?H activation, and a highly regioselective alkyne insertion to afford spirooxindoles and spirodihydrobenzofurans has been achieved. The spirocyclic products were generated in good to excellent yields with complete regiocontrol in a readily scalable procedure.
An enyne cycloisomerization/[5+1] reaction sequence to synthesize tetrahydroisoquinolinones from enyne-enes and CO
Zhuang, Zhe,Li, Chen-Long,Xiang, Yu,Wang, Yu-Hao,Yu, Zhi-Xiang
supporting information, p. 2158 - 2161 (2017/02/19)
An enyne cycloisomerization/[5+1] reaction sequence was developed to synthesize tetrahydroisoquinolinones from linear enyne-enes and CO. The first step is a gold(i)-catalyzed enyne cycloisomerization, generating six-membered-ring-fused vinylcyclopropanes. The second step is a rhodium(i)-catalyzed [5+1] reaction of vinylcyclopropanes with CO. This two-step reaction could also be carried out in one-pot without isolating the cycloisomerization product generated from the first step of this sequence.
Highly Regioselective Palladium-Catalyzed Carboxylation of Allylic Alcohols with CO2
Mita, Tsuyoshi,Higuchi, Yuki,Sato, Yoshihiro
supporting information, p. 16391 - 16394 (2015/11/09)
Various allylic alcohols were carboxylated in the presence of a catalytic amount of PdCl2 and PPh3 using ZnEt2 as a stoichiometric transmetalation agent under a CO2 atmosphere (1atm). This carboxylation proceeded in a highly regioselective manner to afford branched carboxylic acids predominantly. The β,γ-unsaturated carboxylic acid thus obtained was successfully converted into an optically active γ-butyrolactone, a known intermediate of (R)-baclofen.
Enantioselective bromocyclization of allylic amides catalyzed by BINAP derivatives
Kawato, Yuji,Kubota, Akino,Ono, Hiromi,Egami, Hiromichi,Hamashima, Yoshitaka
supporting information, p. 1244 - 1247 (2015/03/14)
A highly enantioselective bromocyclization of allylic amides with N-bromosuccinimide (NBS) was developed with DTBM-BINAP as a catalyst, affording chiral oxazolines with a tetrasubstituted carbon center in high yield with up to 99% ee. By utilizing the bro
Palladium-catalyzed oxidative heck-type allylation of β,β- disubstituted enones with allyl carbonates
Jin, Weiwei,Yang, Qin,Wu, Ping,Chen, Jiping,Yu, Zhengkun
supporting information, p. 2097 - 2102 (2014/07/07)
The palladium-catalyzed oxidative Heck-type allylation of β,β-disubstituted enones, i.e., α-oxoketene dithioacetals, was efficiently realized with allyl carbonates, providing a concise route to highly functionalized dienes. The present synthetic methodology utilizes the substrate activation strategy to activate the C-H bond of β,β-disubstituted enones by introduction of a 1,2-dithiolane functionality to make the enone substrate highly polarized and thus increase its reactivity, demonstrating rare examples for transition metal-catalyzed allylic substitution of ss,ss-disubstituted enones through a Heck-type allylation process.
Unexpected extension of usage of PPh3/CBr4, a versatile reagent: Isomerization of aromatic allylic alcohols
Gong, Wanchun,Liu, Yun,Xue, Jijun,Xie, Zhixiang,Li, Ying
supporting information, p. 1597 - 1599 (2013/02/23)
The PPh3/CBr4-catalyzed isomerization of 2-aromatic allylic alcohols into the corresponding saturated aldehydes or ketones has been achieved at room temperature in good to excellent yields under mild and metal-free conditions. This new methodology has been applied successfully to the synthesis of ibuprofen in four steps.
