Cr( II )介导的醛与官能化手性烯丙基溴内酯的Nozaki-Hiyama烯丙基化为轻松获得β-羟基-芳基/烷基-α-亚甲基-γ-丁内酯铺平了道路,其产率良好,且具有高非对映选择性。随后,在两种 1,10-仲愈创木酚内酯的高效首次不对称全合成中精心策划了一个要求不高的转内酯化反应,作为所开发策略的有价值的扩展。
Construction of polycyclic structures with vicinal all-carbon quaternary stereocenters <i>via</i> an enantioselective photoenolization/Diels–Alder reaction
present in one molecule, they will dramatically increase its synthetic challenge. A chiral titanium promoted enantioselective photoenolization/Diels–Alder (PEDA) reaction allows largely stereohindered tetra-substituted dienophiles to interact with highly active photoenolized hydroxy-o-quinodimethanes, delivering fused or spiro polycyclic rings bearing vicinal all-carbon quaternary centers in excellent
Total Syntheses of Paraconic Acids and 1,10-<i>seco</i>-Guaianolides via a Barbier Allylation/Translactonization Cascade of 3-(Bromomethyl)-2(5<i>H</i>)-furanone
作者:Weilong Liu、Zhimei Yu、Nicolas Winssinger
DOI:10.1021/acs.orglett.0c04165
日期:2021.2.5
palladium-catalyzed Barbier allylation/translactonization cascade reaction was established for the rapid construction of β,γ-disubstituted α-exo-methylene-γ-butyrolactone, an important motif in sesquiterpenes. Dimethyl zinc played significant roles in both steps for the umpolung of π-allylpalladium as a nucleophile and promoting a Lewis acid-mediated translactonization. This sequence showed a broad substrate
The Claisenrearrangement of 1-methyl-2-[(3-methylphenoxy)methyl]cyclopentene in N,N-dimethylformamide gave 5-methyl-2-(1-methyl-2-methylenecyclopentyl)phenol(5) via its trimethylsilyl ether. The methylation of 5, followed by a Simmons-Smith reaction and by the catalytic hydrogenolysis, afforded 3-hydroxycuparene.
Phenylboronic Acid Mediated Triple Condensation Reactions of Phloroglucinol and Unsaturated Carbonyl Compounds
作者:Jeremy D. Pettigrew、Jay A. Cadieux、Simon S. S. So、Peter D. Wilson
DOI:10.1021/ol047578o
日期:2005.2.1
[reaction: see text] A remarkable phenylboronic acid mediated triple condensation reaction of phloroglucinol (1,3,5-trihydroxybenzene) with a series of alpha,beta-unsaturated carbonyl compounds is reported. This experimentally simple reaction afforded novel C3-symmetric 2H-chromene derivatives. These derivatives represent structural analogues of the natural product xyloketal A, which has been reported
Olefin hydroformylation process in a two-phase system
申请人:Studiengesellschaft Kohle mbH
公开号:US06087481A1
公开(公告)日:2000-07-11
The present invention relates to a process for the hydroformylation of terminal and internal olefins in a two-phase system using novel metal catalysts. The two-phase system consists of an aqueous and an organic phase. The metals belong to group VIII of the Periodic Table, e.g., Rh, Ru, Ir, Co or Pd. The ligands for the metals are novel phosphane-modified .beta.-cyclodextrins which are water-soluble.