53544-89-1Relevant academic research and scientific papers
Cadmium iodide mediated allenylation of terminal alkynes for the synthesis of methyl-substituted allenes
Tang, Xinjun,Han, Yulin,Ma, Shengming
, p. 1176 - 1179 (2015)
A cadmium iodide mediated tandem reaction involving amine and two molecules of terminal alkynes for the synthesis of trisubstituted allenes has been developed. By applying this protocol, methyl-substituted allenes may be obtained easily from two molecules of terminal alkynes and pyrrolidine via methyl ketoniminium and propargylic amine formation, 1,5-hydride transfer and β-elimination.
Diastereoselective synthesis of tetrasubstituted propargylamines via hydroamination and metalation of 1-alkynes and their enantioselective conversion to trisubstituted chiral allenes
Periasamy, Mariappan,Reddy, Polimera Obula,Satyanarayana, Iddum,Mohan, Lakavathu,Edukondalu, Athukuri
, p. 987 - 999 (2016)
Reaction of cyclic secondary amines with 1-alkynes and copper(I) chloride at 110-120 °C gives the corresponding alkynylcopper complex, which adds to the iminium ion intermediate formed in situ by hydroamination of 1-alkynes to give the corresponding propargylamine derivatives in up to 94% yield and 99% regioselectivity. The diastereomerically pure chiral propargylamines were obtained in 23-89% yield using optically active 2-benzyl morpholine and N-methyl camphanyl piperazine. These chiral propargylamines are readily converted to the corresponding trisubstitued chiral allenes in 71-89% yields with up to 99% ee upon reaction with ZnBr2 at 120 °C. The results are discussed considering mechanisms involving diastereoselective addition of alkynylcopper complex formed in situ to iminium ions formed in situ regioselectively to produce the corresponding propargylamines, which in turn give the chiral allenes with very high enantioselectivity via an intramolecular 1,5-hydrogen shift in the presence of zinc bromide.
Catalytic Electrophilic Thiocarbocyclization of Allenes
Jiang, Quanbin,Li, Huimin,Zhao, Xiaodan
supporting information, p. 8777 - 8782 (2021/11/17)
An efficient approach via catalytic electrophilic thiocarbocyclization of allenes to construct indene-based sulfides with excellent regioselectivities is disclosed. The reactions were carried out at low temperatures by selenide catalysis in the presence o
Tri(o-tolyl)phosphine for highly efficient Suzuki coupling of propargylic carbonates with boronic acids
Xiao, Junzhe,Luo, Hongwen,Huang, Shan,Qian, Hui,Ma, Shengming
, p. 10451 - 10454 (2018/09/22)
A highly efficient catalytic system consisting of Pd2(dba)3·CHCl3 and tri(o-tolyl)phosphine has been identified for the coupling of propargylic carbonates with different types of organo boronic acids at room temperature. Excellent central-to-axial chirality transfer was also demonstrated.
Enantiodivergent Synthesis of Allenes by Point-to-Axial Chirality Transfer
Armstrong, Roly J.,Nandakumar, Meganathan,Dias, Rafael M. P.,Noble, Adam,Myers, Eddie L.,Aggarwal, Varinder K.
, p. 8203 - 8208 (2018/06/06)
An enantiodivergent method for the synthesis of multiply substituted allenes is described. Highly enantioenriched, point-chiral boronic esters were synthesized by homologation of α-seleno alkenyl boronic esters with lithiated carbamates and eliminated to form axially chiral allene products. By employing either oxidative or alkylative conditions, both syn and anti elimination could be achieved with complete stereospecificity. The process enables the synthesis of either M or P allenes from a single isomer of a point-chiral precursor and can be employed for the enantioselective assembly of di-, tri-, and tetrasubstituted allenes.
Synthesis of multi-substituted allenes from organoalane reagents and propargyl esters by using a nickel catalyst
Shao, Xue Bei,Zhang, Zhen,Li, Qing Han,Zhao, Zhi Gang
, p. 4797 - 4806 (2018/07/13)
A highly efficient and simple route for the synthesis of multi-substituted allenes has been developed by a nickel catalyzed SN2′ substitution reaction of propargyl esters with organic aluminium reagents under mild conditions, which gave the corresponding multi-substituted allenes in good to excellent yields (up to 92%) and high selectivities (up to 99%) at 60 °C for 6 h in THF. Aryls bearing electron-donating or electron-withdrawing groups in propargyl esters gave products in good yields. In addition, the multi-substituted allenes bearing a thienyl or a pyridyl group were obtained in 95-97% selectivities with isolated yields of 72-83%. Furthermore, the SN2′ substitution reaction worked efficiently with propargyl carbonate compounds as well. On the basis of the experimental results, a possible catalytic cycle has been proposed.
Palladium-catalyzed, ligand-free SN2’ substitution reactions of organoaluminum with propargyl acetates for the synthesis of multi-substituted allenes
Shao, Xuebei,Wen, Chang,Zhang, Gang,Cao, Kangping,Wu, Ling,Li, Qinghan
, p. 68 - 75 (2018/06/29)
We describe a convenient method for the synthesis of multi-substituted allenes from SN2′ substitution reactions organoaluminum with propargyl acetates: The SN2′ substitution reaction of organoaluminum (0.4 mmol) with propargyl acetat
Highly Efficient Synthesis of Multi-Substituted Allenes from Propargyl Acetates and Organoaluminum Reagents Mediated by Palladium
Zhang, Zhen,Shao, Xuebei,Zhang, Gang,Li, Qinghan,Li, Xinying
, p. 3643 - 3653 (2017/08/16)
A simple and mild catalytic S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents is reported. The S N 2′ substitution reaction of propargyl acetates with organoaluminum reagents mediated by Pd(PhP 3) 2 Cl 2 (1 mol%)/PPh 3 (2 mol%)/K 2 CO 3 in tetrahydrofuran at 60 °C for 3-4 hours afforded the corresponding multi-substituted allenes in good yields (up to 94%) with high selectivities (up to 99%). The process was simple and easily performed, which offers an efficient method to synthesize the multi-substituted allene derivatives.
Synthesis of Multisubstituted Allenes via Palladium-Catalyzed Cross-Coupling Reaction of Propargyl Acetates with an Organoaluminum Reagent
Zhang, Zhen,Mo, Song,Zhang, Gang,Shao, Xuebei,Li, Qinghan,Zhong, Ying
, p. 611 - 614 (2017/03/11)
We describe a convenient method for the synthesis of multisubstituted allenes from cross-coupling of propargyl acetates with -organoaluminum reagent: The reaction of propargyl acetates with 1.2 equivalents of organoaluminum reagent mediated by Pd(PPh3)2Cl2 (1 mol%)/Ph3P (2 mol%) and K2CO3 in THF may produce tri- or tetrasubstituted allenes in good to excellent yields (83-94%) and high regio-selectivities (up to 99%) at 60 °C in 3-4 hours.
Synthesis of 1,3-Dienes via a Sequential Suzuki-Miyaura Coupling/Palladium-Mediated Allene Isomerization Sequence
Al-Jawaheri, Yassir,Kimber, Marc C.
supporting information, p. 3502 - 3505 (2016/07/23)
We report a facile method for the synthesis of 1,3-dienes by a sequential process consisting of a palladium-catalyzed, base-free, Suzuki-Miyaura coupling/isomerization sequence. This sequence couples boronic acids with propargyl alcohols, generating the requisite allene in situ, followed by conversion of the unactivated allene to its 1,3-diene via a hydro-palladation/dehydro-palladation process. This process is general for a range of boronic acids, including boronic acids with electron-donating and -withdrawing groups, as well as heteroarylboronic acids. Key to this process is the boric acid byproduct of the base-free Suzuki-Miyauru coupling, which generates the required palladium-hydrido complex [H-PdII-OB(OH)2] required for the isomerization.
