66680-87-3Relevant articles and documents
Illuminating Stannylation
Sakamoto, Kyoka,Nagashima, Yuki,Wang, Chao,Miyamoto, Kazunori,Tanaka, Ken,Uchiyama, Masanobu
supporting information, p. 5629 - 5635 (2021/05/04)
We have developed photoboosted stannylation reactions of terminal alkynes (linear-selective hydrostannylation) and fluoroarenes (defluorostannylation), in which the stannyl anion is photoexcited to an excited triplet (T1) stannyl diradical species. This u
Stereostructure Clarifying Total Synthesis of the (Polyenoyl)tetramic Acid Militarinone B. A Highly Acid-Labile N-Protecting Group for Amides ?
Drescher, Christian,Brückner, Reinhard
, p. 6194 - 6199 (2021/08/18)
The 5S, 8′R, and 10′R configurations of militarinone B (3), which is a natural product from Paecilomyces militaris, should equal those in its biosynthetic precursor, militarinone C. The configuration at C-1′ emerged from syntheses of the militarinone B candidates 1′′S- and 1′′R-(5S,8′R,10′R)-3 from the building blocks 9, 11, 14, and 15a while introducing TMB as a more acid-labile N-protecting group for β-ketoamides than DMB. Comparisons of 1′′S- and 1′′R-(5S,8′R,10′R)-3 with natural militarinone B (3; reisolated from Nature) revealed identity versus distinctness.
Iron-Catalyzed Regiodivergent Hydrostannation of Alkynes: Intermediacy of Fe(IV)-H versus Fe(II)-Vinylidene
Liu, Jianguo,Song, Heng,Wang, Tianlin,Jia, Jiong,Tong, Qing-Xiao,Tung, Chen-Ho,Wang, Wenguang
supporting information, p. 409 - 419 (2021/01/12)
We report an iron system, Cp*Fe(1,2-R2PC6H4X), which controls the Markovnikov and anti-Markovnikov hydrostannation of alkynes by tuning the ionic metal-heteroatom bonds (Fe-X) reactivity. The sequential addition of nBu3SnH to the iron-amido catalyst (1, X = HN-, R = Ph) affords a distannyl Fe(IV)-H species responsible for syn-addition of the Sn-H bond across the CC bond to produce branched α-vinylstannanes. Activation of the C(sp)-H bond of alkynes by an iron-aryloxide catalyst (2, X = O-, R = Cy) affords an iron(II) vinylidene intermediate, allowing for gem-addition of the Sn-H to the terminal-carbon producing β-vinylstannanes. These catalytic reactions exhibit excellent regioselectivity and broad functional group compatibility and enable the large-scale synthesis of diverse vinylstannanes. Many new reactions have been established based on such a synthetic Fe-X platform to demonstrate that the initial step of the catalysis is conveniently controlled by the activation of either the tin hydride or the alkyne substrate.
Magnesium-Catalyzed Stereoselective Hydrostannylation of Internal and Terminal Alkynes
Magre, Marc,Szewczyk, Marcin,Rueping, Magnus
supporting information, p. 1594 - 1598 (2020/02/22)
A regio- and stereoselective magnesium-catalyzed hydrostannylation of internal and terminal alkynes has been developed. Excellent yields and selectivities are obtained for a wide range of terminal and internal symmetrical and unsymmetrical alkynes by usin
Synthesis of (Z)-alkene-containing linear conjugated dienyl homoallylic alcohols by a palladium-catalyzed three-component reaction
Horino, Yoshikazu,Sakamoto, Juri,Murakami, Miki,Sugata, Miki
supporting information, p. 1323 - 1327 (2020/08/21)
A synthesis of (Z)-alkene-containing linear conjugated dienyl homoallylic alcohols by using a palladium-catalyzed three-component reaction has been developed. This method shows good functional-group compatibility and generality, with high diastereoselectivity. Additionally, in many cases, the present method controls the alkene stereochemistry of the newly formed C-C bond and overcomes the inherent preference for (E)-alkene formation, giving (Z, E)- and (Z, Z)-products.
A Drastic Effect of TEMPO in Zinc-Catalyzed Stannylation of Terminal Alkynes with Hydrostannanes via Dehydrogenation and Oxidative Dehydrogenation
Kai, Yuichi,Oku, Shinya,Sakurai, Kyoko,Tani, Tomohiro,Tsuchimoto, Teruhisa
, (2019/08/21)
With a system consisting of a catalytic zinc Lewis acid, pyridine, and TEMPO in a nitrile medium, terminal alkynes coupled with HSnBu3, providing alkynylstannanes with structural diversity. The resulting alkynylstannane, without being isolated, could be directly used for Pd- and Cu-catalyzed transformations to deliver internal alkynes and more intricate tin-atom-containing molecules. Mechanistic studies indicated that TEMPOSnBu3 formed in situ from TEMPO and HSnBu3 works to stannylate the terminal alkyne in collaboration with the zinc catalyst, and that both of dehydrogenation and oxidative dehydrogenation processes are uniquely involved in a single reaction. (Figure presented.).
Z-Selective Hydrostannylation of Terminal and Internal C-C Triple Bonds Initiated by the Trityl Cation
Forster, Francis,Rendón López, Victoria M.,Oestreich, Martin
supporting information, p. 2656 - 2659 (2018/09/10)
A metal-free method for the anti-addition of n-Bu3SnH across terminal and internal alkynes, including related α,β-unsaturated carboxyl compounds, is reported. The reaction is initiated by the trityl salt [Ph3C]+[B(C6F5)4]- and proceeds through β-tin-stabilized vinyl cations. Their reduction by hydride transfer from n-Bu3SnH explains the high Z-selectivity in the formation of the vinyl stannanes.
Ynamide Carbopalladation: A Flexible Route to Mono-, Bi- and Tricyclic Azacycles
Campbell, Craig D.,Greenaway, Rebecca L.,Holton, Oliver T.,Walker, P. Ross,Chapman, Helen A.,Russell, C. Adam,Carr, Greg,Thomson, Amber L.,Anderson, Edward A.
supporting information, p. 12627 - 12639 (2015/09/01)
Bromoenynamides represent precursors to a diversity of azacycles by a cascade sequence of carbopalladation followed by cross-coupling/electrocyclization, or reduction processes. Full details of our investigations into intramolecular ynamide carbopalladation are disclosed, which include the first examples of carbopalladation/cross-coupling reactions using potassium organotrifluoroborate salts; and an understanding of factors influencing the success of these processes, including ring size, and the nature of the coupling partner. Additional mechanistic observations are reported, such as the isolation of triene intermediates for electrocyclization. A variety of hetero-Diels-Alder reactions using the product heterocycles are also described, which provide insight into Diels-Alder regioselectivity.
A one-pot allylation-hydrostannation sequence with recycling of the intermediate tin waste
Ghosh, Banibrata,Amado-Sierra, Maria Del Rosario I.,Holmes, Daniel,Maleczka, Robert E.
supporting information, p. 2318 - 2321 (2014/05/20)
A one-pot allylation and hydrostannation of alkynals where the tin byproduct formed in the first step of the reaction is recycled and used in the second step of the sequence is presented. Specifically, a BF3· OEt2-promoted allylstannation of the aldehyde moiety in the alkynal is followed by the introduction of polymethylhydrosiloxane (PMHS) and catalytic B(C6F5)3, which convert the tin byproduct of the allylation into Bu3SnH, which then hydrostannates the alkyne in the molecule. 119Sn and 11B NMR data suggest an organotin fluoride species is formed during the allylation step and involved in the tin recycling step.
Novel catalyst system for hydrostannation of alkynes
Gupta, Sreya,Do, Youngshil,Lee, Jin Hee,Lee, Miryeong,Han, Junghoon,Rhee, Young Ho,Park, Jaiwook
, p. 1267 - 1271 (2014/04/03)
A catalyst system was developed for the highly regio-and stereoselective hydrostannation of a range of alkynes with tributylstannane under mild conditions. The active catalytic species was generated from a stable diruthenium complex by illuminating household fluorescent light (30 W) at room temperature.
