177608-64-9Relevant academic research and scientific papers
Synthetic Routes to Allenic Acids and Esters and Their Stereospecific Conversion to Butenolides
Marshall, James A.,Wolf, Mark A.,Wallace, Eli M.
, p. 367 - 371 (1997)
The synthesis of allenic acids and esters and their conversion to butenolides has been examined in some detail. Racemic butenolides 10 are efficiently prepared from the esters 8 through treatment with BCl3 and exposure of the derived acid 9 to catalytic AgNO3 in acetone. Conversion of the enantioenriched allenylstannane (S)-17 to the acid 18 through lithiation and subsequent carboxylation with CO2 afforded racemic product. The enantioenriched propargylic mesylates 16 and 22 afforded the allenic esters 19 and 23 with inversion of configuration through treatment with Pd(Ph3P)4, CO, and the appropriate alcohol in THF. These reactions proceeded with ca. 10% or less of racemization. The allenic esters 23 yielded the iodobutenolides 24 by reaction with IBr. Hydrogenolysis to the butenolide 25 was achieved with Pd(PPh3)4 and Bu3SnH. Alternatively, the allenic acids 27 could be prepared directly from mesylates 22 with Pd(PPh3)4 and CO in aqueous THF. Cyclization to the butenolides 25 was achieved, as before, with catalytic AgNO3.
Rhodium(III)-Catalyzed Annulative Coupling of Sulfoxonium Ylides and Allenoates: An Arene C-H Activation/Cyclopropanation Cascade
Lou, Jiang,Wang, Quannan,Zhou, Yong-Gui,Yu, Zhengkun
supporting information, p. 9217 - 9222 (2019/11/19)
Rhodium(III)-catalyzed annulative coupling of sulfoxonium ylides with allenoates was achieved, forming highly functionalized cyclopropanes with a quaternary carbon center by means of the sulfoxonium ylide functionality as a traceless bifunctional directin
The Renaissance of an Old Problem: Highly Regioselective Carboxylation of 2-Alkynyl Bromides with Carbon Dioxide
Miao, Bukeyan,Li, Gen,Ma, Shengming
, p. 17224 - 17228 (2016/01/25)
A steric effect-controlled, zinc-mediated carboxylation of different 2-alkynyl bromides under an atmospheric pressure of CO2 has been developed by careful tuning of different reaction parameters, including the metal, solvent, temperature, and additive. 2-Substituted 2,3-allenoic acids were afforded from primary 2-alkynyl bromides, whereas the carboxylation of secondary 2-alkynyl bromides yielded 3-alkynoic acids in decent yields. A rationale for the observed regioselectivity has been proposed.
Synthesis of terminal allenes through copper-mediated cross-coupling of ethyne with N-tosylhydrazones or α-diazoesters
Ye, Fei,Wang, Chengpeng,Ma, Xiaoshen,Hossain, Mohammad Lokman,Xia, Ying,Zhang, Yan,Wang, Jianbo
, p. 647 - 652 (2016/09/12)
Ethyne is employed as coupling partner in coppermediated cross-coupling reactions with N-tosylhydrazones and α-diazoacetate, leading to the development of a new synthetic method for terminal allenes. With this novel coupling method, the terminal allenes w
