Generation of α,β-Unsaturated Platinum Carbenes from Homopropargylic Alcohols: Rearrangements to Polysubstituted Furans
摘要:
A number of diversely substituted furans are synthesized via a cycloisomerization process that goes through a unique metal carbene species. Both ligand structure and the nature of the leaving group are evaluated. The characteristics of the carbene intermediate can be modulated, resulting in highly selective hydrogen or silicon group migrations.
Transannular [4+3] Cycloadditions of Macrocyclic Epoxy Ketones
作者:Diana Chan、Yu Chen、Kam-Hung Low、Pauline Chiu
DOI:10.1002/chem.201800019
日期:2018.2.16
dienophiles derived from macrocyclic epoxy ketones produce fused ring systems having central cycloheptane subunits. In some cases, the base directly induced cycloisomerization of the epoxy ketones to yield the cycloadducts; in others, the epoxy ketones were transformed into their corresponding enolsilanes before undergoing cycloaddition. Enantiomerically enriched tricyclic arrays were obtained from cycloadditions
.A protocol for Pd-catalyzed intra- and intermolecular 2,5-alkoxyarylation reactions of furans to diastereospecifically synthesize two series of spirooxindoles is reported. This protocol likely involves an intramolecular dearomatizing Heck-type [small alpha]-arylation of...
Acid-Catalyzed Intramolecular Ring-Opening Reactions of Cyclopropanated Oxabenzonorbornadienes with Carboxylic Acid Nucleophiles
作者:William Tam、Angel Ho、Austin Pounder、Samuel Koh、Matthew P. Macleod、Emily Carlson
DOI:10.1055/a-1672-2260
日期:2022.3
(CPOBDs) to undergo ring-opening reactions in mild acidic conditions. The optimized reaction conditions involve the use of pTsOH in DCE at 90 °C. Two regioisomers are formed but the reactions are highly regioselective towards type 3 ring-opened products. It was observed that substitution at the C5 and aryl positions of CPOBD significantly hinders the ring-opening reactions leading to decreased yields of
Acid-catalyzed intramolecular ring-opening reactions of cyclopropanated oxabenzonorbornadienes with alcohol nucleophiles
作者:Christopher Wicks、Samuel Koh、Austin Pounder、Emily Carlson、William Tam
DOI:10.1016/j.tetlet.2019.151228
日期:2019.11
An investigation of intramolecular ring-opening reactions of various cyclopropanated oxabenzonorbornadienes (CPOBDs) with alcohol nucleophiles is reported, which forms two regioisomeric products in good yields. The effect of various tether lengths was explored, wherein increasing the alcohol tether length to 4 or 5 carbons exclusively generated Type 3 products in good yield, while C-1-hydroxymethyl