Enantioselective alkynylations of aromatic and aliphatic aldehydes catalyzed by terpene derived chiral amino alcohols
作者:Cian Christopher Watts、Praveen Thoniyot、Lacie C. Hirayama、Talia Romano、Bakthan Singaram
DOI:10.1016/j.tetasy.2005.03.036
日期:2005.5
Enantioselective alkynyl zinc additions to aromatic and aliphatic aldehydes have been studied using terpene derived chiral amino alcohol ligands. The limonene derived amino alcohol (1R,2R,5S)-2-methyl-5-(1-methylethenyl)-2-(1-pyrrolidinyl)cyclohexanol gave the most promising results. Chiral propargylic alcohols were obtained in good yields and moderate enantioselectivities (up to 60%).
DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives
作者:Mrinal K. Bera、Rimpa De、Antony Savarimuthu、Tamal Ballav、Pijush Singh、Jayanta Nanda、Avantika Hasija、Deepak Chopra
DOI:10.1055/s-0040-1707909
日期:2020.10
A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondarypropargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer–Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy
The trimethylgallium reagent was found to promote the addition of phenylacetylene to various aromatic and aliphatic aldehydes. This reaction was efficiently carried out in anhydrous CH2Cl2 at room temperature under mild conditions and the corresponding propargylic alcohols were obtained in good to excellent yields up to 98%.
1,1′-Binaphthyl ligands with bulky 3,3′-tertiaryalkyl substituents for the asymmetric alkyne addition to aromatic aldehydes
作者:Qin Wang、Shan-Yong Chen、Xiao-Qi Yu、Lin Pu
DOI:10.1016/j.tet.2007.03.080
日期:2007.5
The BINOL ligand (R)-2 that contains bulky 3,3'-tertiaryalkyl groups shows improved catalytic properties than the previously reported 3,3'-substituted BINOL ligands in the asymmetric alkyne addition to aromatic aldehydes. It can catalyze the phenylacetylene addition to aromatic aldehydes with high enantioselectivity (86 - 94% ee) and good yields without using Ti(O(i)Pr)(4) and a Lewis base additive
A new and general one-pot synthesis of propargyl alcohols from esters
作者:Min Jung Chae、Ah Ram Jeon、Tom Livinghouse、Duk Keun An
DOI:10.1039/c0cc04597g
日期:——
Intermediates easily prepared by partial reduction of various esters with LDBBA as a reducing agent smoothly react with lithium acetylides to give propargylalcohols, without isolation of partial reduction intermediates, in good yields (73-83%).