14399-53-2Relevant articles and documents
Enantioselective synthesis and structure revision of solandelactone E
Davoren, Jennifer E.,Martin, Stephen F.
, p. 510 - 511 (2007)
The first total synthesis of solandelactone E has been achieved by a novel and convergent strategy that required 23 steps. The synthesis features a diastereoselective acetal-directed cyclopropanation of an electron-deficient diene, a Sharpless asymmetric dihydroxylation, and a [2,3]-sigmatropic rearrangement of a selenoxide intermediate. Copyright
Formation of transition metal carbenes using haloalkylzinc reagents
Poverenov, Elena,Milstein, David
, p. 3189 - 3191 (2007)
A new reaction of haloalkylzinc compounds, leading to transition metal carbenes, is described; halomethylzinc and halobenzylzinc compounds react with ruthenium and iridium complexes to form methylene and benzylidene complexes, including the Grubbs catalyst. The Royal Society of Chemistry.
Forming Stereogenic Centers in Acyclic Systems from Alkynes
Vabre, Roxane,Island, Biana,Diehl, Claudia J.,Schreiner, Peter R.,Marek, Ilan
, p. 9996 - 9999 (2015)
The combined carbometalation/zinc homologation followed by reactions with α-heterosubstituted aldehydes and imines proceed through a chair-like transition structure with the substituent of the incoming aldehyde residue preferentially occupying a pseudo-axial position to avoid the two gauche interactions. The heteroatom in the axial position produces a chelated intermediate (and not a Cornforth-Evans transition structure for α-chloro aldehydes and imines) leading to a face differentiation in the allylation reaction. This method provides access to functionalized products in which three new carbon-carbon bonds and two to three stereogenic centers, including a quaternary one, were created in acyclic systems in a single-pot operation from simple alkynes. All-carbon quaternary stereocenter: The combined carbometalation/zinc homologation of alkynes followed by reactions with α-heterosubstituted aldehydes and imines provides access to functionalized acyclic adducts. These adducts obtained in a single-pot reaction have three new carbon-carbon bonds and two to three stereogenic centers, including a quaternary carbon stereocenter.
Stereoselective Synthesis of (S)- And (N)-Cyclopropyl-Fused Carbocyclic Nucleosides Using Stereoselective Cyclopropanation
Hyun, Young Eum,Jeong, Lak Shin,Kim, Hong-Rae
, p. 9828 - 9837 (2021)
To determine which sugar conformation is favorable in binding to peroxisome proliferator-activated receptors, the conformationally locked south (S) and north (N) analogues were asymmetrically synthesized using a bicyclo[3.1.0]hexane template. The (S)-conformer was synthesized by employing "reagent-controlled"Charette asymmetric cyclopropanation in a 100% stereoselective manner, whereas the (N)-conformer was stereoselectively synthesized by using "substrate-controlled"hydroxyl-directed Simmons-Smith cyclopropanation as a key step.
Enantioselective Synthesis of cis- A nd trans-Borocyclopropylmethanol: Simple Building Blocks to Access Heterocycle-Substituted Cyclopropylmethanols
Charette, André B.,Navuluri, Chandrasekhar,Siddiqui, Saher H.
, p. 3834 - 3846 (2019/10/11)
An enantioselective and non-oxidative methodology was developed to obtain enantioenriched cyclopropyl boronates using a diethanolamine-promoted selective decomplexation of dioxaborolane. The non-oxidative decomplexation of the dioxaborolane ligand from the cyclopropylmethoxide species formed in the dioxaborolane-mediated Simmons-Smith cyclopropanation reaction provided the enantio?-enriched CIDA-based (CIDA = N-cyclohexyliminodiacetic acid) boro?-cyclopropane in 92% yield and 95.6:4.4 er. A robustness screen has shown diethanolamine to be compatible with esters, carbamates and N-heterocycles, providing a tool to access enantioenriched cyclopropanes carrying not only base-sensitive but oxidizable functional groups as well. Diethanolamine was found to be compatible with the modified zinco-cyclopropanation reaction of allyl alcohol to remove residual dioxaborolane from the corresponding cis-N-heterocycle cyclopropylmethanol, thereby leading to improved yields.
Mild Ring-Opening 1,3-Hydroborations of Non-Activated Cyclopropanes
Wang, Di,Xue, Xiao-Song,Houk, Kendall N.,Shi, Zhuangzhi
supporting information, p. 16861 - 16865 (2018/11/27)
The Brown hydroboration reaction, first reported in 1957, is the addition of B?H across an olefin in an anti-Markovnikov fashion. Here, we solved a long-standing problem on mild 1,3-hydroborations of non-activated cyclopropanes. A three-component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring-opening of cyclopropanes following the anti-Markovnikov rule, under mild reaction conditions. Density functional theory (M06-2X) calculations show that the preferred pathway involves a cationic boron intermediate which is quenched by hydride transfer from the silane.
B(C6F5)3-Catalyzed Ring Opening and Isomerization of Unactivated Cyclopropanes
Zhang, Zi-Yu,Liu, Zhi-Yun,Guo, Rui-Ting,Zhao, Yu-Quan,Li, Xiang,Wang, Xiao-Chen
supporting information, p. 4028 - 4032 (2017/03/27)
Catalytic amounts of B(C6F5)3 promote the ring opening and subsequent isomerization of a series of unactivated cyclopropanes to afford terminal olefins in good yields when a hydrosilane and 2,6-dibromopyridine are employed as additives.
Synergistic effect of additives on cyclopropanation of olefins
Cheng, Donghao,Huang, Deshun,Shi, Yian
supporting information, p. 5588 - 5591 (2013/09/12)
An efficient cyclopropanation of olefins with Zn(CH2I) 2, a catalytic amount of CCl3CO2H, and 1,2-dimethoxyethane at room temperature is described. A wide variety of olefins, including acid-sensitive substrates,
Stability, reactivity, solution, and solid-state structure of halomethylzinc alkoxides
Charette,Molinaro,Brochu
, p. 12160 - 12167 (2007/10/03)
In this paper, we report our findings regarding the development of a Lewis acid-catalyzed cyclopropanation of allylic alcohols with bis(iodomethyl)zinc. Iodomethylzinc alkoxides can be formed by treatment of an alcohol with bis(iodomethyl)zinc. These species are not prone to undergo cyclopropanation at low temperature but the addition of a Lewis acid in catalytic amounts induces the cyclopropanation reaction. Using this procedure, we demonstrated that the Lewis acid-catalyzed pathway significantly overwhelms the uncatalyzed one. This paper describes fundamental issues regarding the preparation and stability of halomethyl zinc alkoxides in solution as well as their aggregation state in solution and solid-state structures. Furthermore, the competition reaction between the inter- vs intramolecular cyclopropanation will be studied. Finally, we will discuss the possible activation pathways to explain the Lewis acid activation of halomethylzinc alkoxides. These findings provided new insights on the reactivity of ROZnCH2I and established the groundwork for the elaboration of an enantioselective version of the reaction.
