Access to Triazolopiperidine Derivatives via Copper(I)‐Catalyzed [3+2] Cycloaddition/Alkenyl C−N Coupling Tandem Reactions
作者:Guorong Xiao、Kaifu Wu、Wei Zhou、Qian Cai
DOI:10.1002/adsc.202100955
日期:2021.11.9
A copper-catalyzed [3+2] cylcoaddition/ alkenyl C−N coupling tandem reaction was demonstrated. It provided a method for the formation of triazolopiperidine skeletons.
One-Pot Synthesis of α-Iodo-Substituted α,β-Unsaturated Aldehydes from Propargylic Alcohols
作者:Shufeng Chen、Jianbo Wang
DOI:10.1021/jo070230x
日期:2007.6.1
An efficient one-pot method for the preparation of α-iodo-substituted α,β-unsaturatedaldehydes (α-iodoenals) from propargylic alcohol is developed. The reaction proceeds via an iodoallene intermediate, which is generated in situ by the reaction of propargylic alcohol with aqueous HI. The iodoallene intermediate is further transformed to an α-iodoenal derivative in good overall yield by oxidation with
Instead, itsmolecular structure is planar, as experimentally determined using single crystal X-ray diffraction, and confirmed theoretically by DFT calculations on the single molecule and the halogen pair paired molecules, therefore ruling out crystal packing forces as a principal factor leading to planarity. Indeed, planarity is ascribed to the carbonyl double bond, as when this bond is saturated on forming
Facile α-bromination of cyclic enones and linear enals involving N-bromosuccinimide and 1–2 equiv of pyridine-N-oxide is reported herein. α-Bromination of linear enals was found to proceed with double bond geometry retention.
Gold(I) catalysed cycloisomerisation of β-hydroxy propargylic esters to dihydropyrans/2H-pyrans via allene intermediates
作者:Ramesh Kotikalapudi、K.C. Kumara Swamy
DOI:10.1016/j.tet.2013.07.003
日期:2013.9
Efficient cycloisomerisation of β-hydroxy propargylic esters to dihydropyrans/2H-pyrans via 1,3-carboxylate migration followed by regioselective hydroxyl addition to the transient allene intermediate catalysed by Ph3PAuCl/AgSbF6 is presented. Similar reactions on phosphorylated precursors led to phosphono-furans and phosphono-pyrans. In a few cases, self-condensation of β-hydroxy propargylic esters