A convenient one pot allylation of aldehydes with allyliciodides prepared in situ from allylicalcohols by usingtrimethylsilylchloride and sodiumiodide proceeds smoothly in the presence of meta...
Bi(cyclopentyl)diol-Derived Boronates in Highly Enantioselective Chiral Phosphoric Acid-Catalyzed Allylation, Propargylation, and Crotylation of Aldehydes
作者:Jinping Yuan、Pankaj Jain、Jon C. Antilla
DOI:10.1021/acs.joc.0c01646
日期:2020.10.16
catalytic addition of bi(cyclopentyl)diol-derived boronates to aldehydes promoted by chiralphosphoricacids, allowing for the formation of enantioenriched homoallylic, propargylic, and crotylic alcohols (up to >99% enantiomeric excess (ee), diastereomeric ratio (dr) >20:1). These boronate substrates provided superior enantioselectivities, allowing for the reactions to proceed with low catalyst loading
Catalytic Allylation of Aldehydes Using Unactivated Alkenes
作者:Shun Tanabe、Harunobu Mitsunuma、Motomu Kanai
DOI:10.1021/jacs.0c04735
日期:2020.7.15
and a chromium complex catalyst, enabling catalytic allylation of aldehydes with simplealkenes, including feedstock lower alkenes. The reaction proceeded under visible-light irradiation at room temperature and with high functional group tolerance. The reaction was extended to an asymmetric variant by employing a chiral chromium complex catalyst.
1-Substituted or 3-substituted prop-2-en-1-ols cause syn-diastereoselective carbonyl allylation with tin(II) iodide and tetrabutylammonium iodide via the formation of 3-substituted prop-2-enylpolyiodotins to produce syn-1,2-disubstituted but-3-en-1-ols.
The utility of the new class of chiral ligand, tethered bis(8-quinolinol) (TBOxH), is further explored. Its chromium complex, TBOxCr(III)Cl, effectively catalyzes the Nozaki-Hiyama allylation reactions of various aldehydes at room temperature with high yield (up to 95%) and high enantioselectivity (up to 99% ee). The scope of the present method is shown to be wide, and this method represents an efficient