The first controllable, regioselectiveradicalamination of allenes with N‐fluoroarylsulfonimide is described to proceed under very mild reaction conditions. With this methodology, a general and straightforward route for the synthesis of both allenamides and fluorinated tetrasubstitutedalkenes was realized from a wide range of terminal and internal allenes.
Mono- and 1,3-disubstituted allenes were synthesized from the corresponding propargylamines via palladium-catalysed hydride-transferreaction. In the current transformation, propargylic amines can be handled as allenyl anion equivalents and introduced into various electrophiles to be transformed into allenes under palladium-catalyzed conditions.
Highly Regioselective Synthesis of Trisubstituted Allenes via Lithiation of 1-Aryl-3-alkylpropadiene, Subsequent Transmetalation, and Pd-Catalyzed Negishi Coupling Reaction
作者:Jinbo Zhao、Yu Liu、Shengming Ma
DOI:10.1021/ol8001909
日期:2008.4.1
A novel methodology for the synthesis of trisubstituted allenes is reported. Lithiation of 1-aryl-3-alkylpropadienes and subsequent transmetalation with zinc bromide followed by Pd-catalyzed Negishi couplingreactions with halides afforded the corresponding trisubstituted allenes in a highly regioselective fashion with moderate to excellent yields. A plausible regioselective lithiation mechanism was
Intermolecular rhodium catalyzed hydroacylation of allenes: the regioselective synthesis of β,γ-unsaturated ketones
作者:Helen E. Randell-Sly、James D. Osborne、Robert L. Woodward、Gordon S. Currie、Michael C. Willis
DOI:10.1016/j.tet.2009.03.054
日期:2009.6
A variety of β-S-substituted aldehydes undergo efficient and regioselectiverhodiumcatalyzedhydroacylation reactions with 1,3-disubstituted and 1,1,3-trisubstituted allenes, to deliver β,γ-unsaturated ketone products. Regioselectivites are controlled primarily by steric factors. The reactions are catalyzed by the complex [Rh(dppe)]ClO4.
Pd‐Catalyzed Heck‐Type Reactions of Allenes for Stereoselective Syntheses of Substituted 1,3‐Dienes
作者:Logan E. Vine、Jennifer M. Schomaker
DOI:10.1002/chem.202103507
日期:2022.1.3
A stereoselective synthesis of (Z,E)-dienes from allenes is described. The method employs a Heck-type reaction catalyzed by tris(dibenzylideneacetone) dipalladium, Pd2dba3 and a CyJohnPhos ligand and does not require a leaving or directing group on the allene. The stereochemistry of both olefins of the diene is set simultaneously using both A1,3 strain and eclipsing interactions during the β-hydride