43019-63-2Relevant academic research and scientific papers
Ni-catalyzed direct carboxylation of propargylic alcohols with carbon dioxide
Yamahira, Tatsuya,Onodera, Gen,Fukuda, Tsutomu,Kimura, Masanari
supporting information, p. 853 - 855 (2021/05/19)
The carboxylation of propargylic alcohols containing a silyl group at the terminal position was conducted in a CO2 atmosphere at atmospheric pressure in the presence of a nickel catalyst and diethylzinc. Here, CO2 was used as not only the C1 source but also the promoter of the COH cleavage processes for the oxidative addition of propargylic alcohols.
Direct Access to Allenylphosphine Oxides via a Metal Free Coupling of Propargylic Substrates with P(O)H Compounds
Yang, Chun-Hua,Fan, Huihui,Li, Huimin,Hou, Shenyin,Sun, Xiangkun,Luo, Donghao,Zhang, Yinchao,Yang, Zhantao,Chang, Junbiao
supporting information, p. 9438 - 9441 (2019/11/20)
A direct and convenient approach for the coupling of propargylic substrates with diphenylphosphine oxide in the presence of Tf2O and 2,6-lutidine has been developed. The method provides a general approach for the construction of attractive allenylphosphoryl skeletons with high atom and step economy under metal free conditions.
Access to Stereodefined (E)-2-Silylallylboronates via Regioselective Chloroboration of Allenylsilanes
Yang, Zhantao,Liu, Tingjie,Chen, Xixi,Wan, Ranran,Li, Yang,Wang, Xianzhen,Yang, Chun-Hua,Chang, Junbiao
supporting information, p. 9541 - 9544 (2019/11/20)
A catalyst-free method for the highly regioselective chloroboration of allenylsilanes is described. In the presence of BCl3 and 2,6-lutidine, chloroboration of allenylsilanes proceeds smoothly without any catalyst, and the product could be treated with pinacol to afford the corresponding pinacol borates in one-pot reaction. This reaction provides a direct approach to construct valuable 2-silylallylboronate frameworks with operational simplicity and high atom-economy.
Si-directed regiocontrol in asymmetric Pd-catalyzed allylic alkylations using C1-ammonium enolate nucleophiles
Fyfe, James W.B.,Kabia, Omaru M.,Pearson, Colin M.,Snaddon, Thomas N.
supporting information, p. 5383 - 5391 (2018/04/23)
Cooperative catalysis enables the direct enantioselective α-allylation of linear prochiral esters using Si-substituted allyl electrophiles. The Si-substituent directs the regioselectivity of enantioselective bond formation and provides products containing synthetically versatile pentafluorophenyl ester and vinylsilane moieties. Critical to the efficacy of this process was the recognition that the ancillary ligand on palladium could be altered to prevent formation of a deleterious ether by-product, whilst retaining enantioselectivity through the Lewis base catalyst. Flexibility such as this is unique to cooperative catalysis events and provides efficient access to an array of enantioenriched products that are orthogonally functionalized and easily modified.
Iridium-Catalyzed Enantioselective Hydrogenation of Vinylsilanes
Wang, Aie,Bernasconi, Maurizio,Pfaltz, Andreas
supporting information, p. 2523 - 2529 (2017/08/16)
We have screened a diverse array of iridium complexes derived from chiral N,P ligands as catalysts for the asymmetric hydrogenation of vinylsilanes, a transformation for which generally applicable catalysts were lacking. Several catalysts emerged from thi
Synthesis and Isolation of Organogold Complexes through a Controlled 1,2-Silyl Migration
McGee, Philippe,Bellavance, Gabriel,Korobkov, Ilia,Tarasewicz, Anika,Barriault, Louis
supporting information, p. 9662 - 9665 (2015/06/30)
During our efforts toward the synthesis of naturally occurring polyprenylated polycyclic acylphloroglucinol using a AuI-catalyzed 6-endo dig carbocyclization, we isolated stable vinyllic gold intermediates. Optimization lead to isolated yields of up to 98 %, using 2-(di-tert-butylphosphino)biphenyl as the ligand. This transformation is derived from a silyl rearrangement that can be fully controlled according to the nature of the substituent on the ynone. This selective transformation does not require basic conditions to prevent protodeauration. These vinylgold complexes are the first isolated intermediates during a silyl migration with gold(I). More than 16 new organogold complexes were synthesized and characterized by single-crystal X-ray diffraction. Reactivity of these complexes is also presented.
Stereoselective synthesis of E,Z-configured 1,3-dienes by ring-closing metathesis. Application to the total synthesis of lactimidomycin
Gallenkamp, Daniel,Fuerstner, Alois
supporting information; experimental part, p. 9232 - 9235 (2011/08/06)
Strategic positioning of a silyl group on the diene unit of a diene-ene substrate allows rigorous regio- and stereocontrol to be exerted during metathesis-based macrocyclization reactions. The versatility of this concise approach to E,Z-configured 1,3-die
Enantioselective synthesis of allylsilanes bearing tertiary and quaternary si-substituted carbons through Cu-catalyzed allylic alkylations with alkylzinc and arylzinc reagents
Kacprzynski, Monica A.,May, Tricia L.,Kazane, Stephanie A.,Hoveyda, Amir H.
, p. 4554 - 4558 (2008/09/17)
All sorts of allylsilanes including, for the first time, those that contain a Si-bonded quaternary carbon, were synthesized through efficient and highly enantioselective Cu-catalyzed asymmetric allylic alkylations. Reactions may involve dialkyl- as well as diarylzinc reagents and are promoted by various chiral N-heterocyclic carbene complexes.
Tandem Base-Promoted Ring-Opening/Brook Rearrangement/Allylic Alkylation of O-Silyl Cyanohydrins of β-Silyl-α,β-epoxyaldehyde: Scope and Mechanism
Sasaki, Michiko,Kawanishi, Eiji,Nakai, Yoshio,Matsumoto, Tatsuya,Yamaguchi, Kentaro,Takeda, Kei
, p. 9330 - 9339 (2007/10/03)
Metalated O-silyl cyanohydrins of β-silyl-α,β -epoxyaldehyde have been found to serve as functionalized homoenolate equivalents by a tandem sequence involving base-promoted ring opening of the epoxide, Brook rearrangement, and alkylation of the resulting
Allylsilane-modified amino acids from the Claisen rearrangement
Mohamed, Mustafa,Brook, Michael A.
, p. 4165 - 4181 (2007/10/03)
The Claisen rearrangement of the N-protected, silylated allyl glycinates 11 and 12 led to the formation of allyl/silyl-functionalized amino acids 13 and 14 in yields up to 80%. The diastereoisomer ratio varied from 2:1 to 29:1 for 11mb, and from 2:1 to 46:1 (syn/anti) for 12mb, depending on reaction conditions, as shown by X-ray crystallographic analysis of 14mb. The relationship between the size of the alkyl groups on the chlorosilane reagent (Me2R″SiCl, R″ = Cl, Me, t-Bu, Ph) used as an enolate trap and the observed stereoselectivity was investigated in the case of the Ireland - Claisen variant. Me3SiCl gave the best results. However, the size of the alkyl groups on the silylated ester (Me2R″Si, R = Me, t-Bu, Ph, i-Pr) did not exert a significant effect on the diastereoselectivity or yield of the rearrangement.
