Efficient 1,2-Addition of Aryl- and Alkenylboronic Acids to Aldehydes Catalyzed by the Palladium/Thioether−Imidazolinium Chloride System
摘要:
[GRAPHICS]The high level of catalyst performance was attainable in the palladium-catalyzed 1,2-addition of aryl-, heteroaryl-, and alkenylboronic acids to aromatic, heteroaromatic, and aliphatic aldehydes using thioether-imidazolinium chloride L5 as a heterobidentate carbene ligand precursor.
An enantioselective oxa-Piancatelli reaction was established for the first time using a chiral vanadium(V) catalyst. The dual Brønsted and Lewis acid properties of the vanadium catalyst afforded 4-hydroxycyclopent-2-enone derivatives in up to 90% yields and with 93 : 7 enantiomeric ratios, as well as >20 : 1 diastereomeric ratios.
Efficient synthesis of 4-hydroxycyclopentenones: dysprosium(III) triflate catalyzed Piancatelli rearrangement
作者:David Fisher、Leoni I. Palmer、Jonathan E. Cook、Jessica E. Davis、Javier Read de Alaniz
DOI:10.1016/j.tet.2014.03.007
日期:2014.7
4-Hydroxycyclopentenones represent a privileged scaffold in chemical synthesis. A dysprosium(III) trifluoromethanesulfonate catalyzed rearrangement of furylcarbinols to 4-hydroxycyclopentenones via a 4π electrocyclization has been developed. The catalytic Piancatelli rearrangement affords a single trans-diastereomer from both aryl and alkyl substituted furylcarbinols.
Divergent Synthesis of Dihydropyranone Stereoisomers via N‐Heterocyclic Carbene Catalysis
作者:Changgui Zhao、Jian Wang
DOI:10.1002/adsc.201801639
日期:2019.4
We recently developed a novel chiral N‐heterocyclic carbene (NHC) catalyzed dynamic kinetic enantioselective acylation (DKEA) and dynamic kinetic diastereoselective acylation (DKDA) of Achmatowicz rearrangement products to generate useful intermediates for the further synthesis of carbohydrates. In this update, we describe a divergent NHC catalytic strategy for the stereoselective preparation of all
A chiral N,N′-dioxide/cobalt(II) complex catalyzed highly diastereoselective and enantioselective tandem aza-Piancatelli rearrangement/intramolecular Diels–Alderreaction has been disclosed. Various valuable hexahydro-2a,5-epoxycyclopenta[cd]isoindoles bearing six contiguous stereocenters have been obtained in good yields with excellent diastereo- and enantio-selectivities from a wide range of both
已公开了一种手性N,N'-二氧化物/钴(II)配合物,催化高度非对映选择性和对映选择性的串联氮杂-Piancatelli重排/分子内狄尔斯-阿尔德反应。从各种现成的2-呋喃基甲醇和N-(呋喃-2)中,以良好的收率获得了具有六个非连续立体中心的高收率的各种有价值的六氢-2 a,5-环氧环戊基[ cd ]异吲哚,并具有六个连续的立体中心。-基甲基)苯胺。
An efficient organocatalyticenantioselective aza‐Piancatelli rearrangement is disclosed. The powerful process provides rapid access to valuable chiral 4‐amino‐2‐cyclopentenone building blocks from readily available 2‐furfurylcarbinols with excellent chemo‐, enantio‐, and diastereoselectivities under mild reaction conditions.