A flexible synthetic route to the 16-membered tetramate-embedding macrocyclic scaffold present in various polycyclic tetramate macrolactams (PTMs) was developed which differs from the seminal synthesis of ikarugamycin by Boeckman Jr. in protecting groups and the order of connections. We also devised a short approach to various stereoisomers of the 5/5/6-tricarbocyclic motif found in discodermide and
A novel nickel-catalyzed remote arylation of alkenyl aldehydes triggered by radical alkylation with tertiary α-carbonyl alkyl bromides is described, thus producing a quaternary carbon center containing ketones in promising yields with broad functional group compatibility. Preliminary mechanistic studies suggest that the combination of a 1,n-HAT (n = 5 or 6) from alkyl radicals to aldehyde C–H bonds
Palladium-Catalyzed Remote Aryldifluoroalkylation of Alkenyl Aldehydes
作者:Xingliang Nie、Cungui Cheng、Gangguo Zhu
DOI:10.1002/anie.201611697
日期:2017.2.6
A palladium‐catalyzed three‐component reaction between fluoroalkyl bromides, arylboronic acids, and alkenyl aldehydes has been developed and provides facile access to 5‐, 6‐, or 7‐difluoroalkylated ketones under very mild reaction conditions. The resultant products can be smoothly converted into CF2‐containing tetrahydronaphthalenes by a novel silver‐catalyzed intramolecular decarboxylative cyclization
Enantio‐ and Diastereoselective, Lewis Base Catalyzed, Cascade Sulfenoacetalization of Alkenyl Aldehydes
作者:Anastassia Matviitsuk、Scott E. Denmark
DOI:10.1002/anie.201906535
日期:2019.9.2
catalytic, enantio-, and diastereoselective formation of sulfenyl acetals bearingmultiplestereogeniccenters is reported. Alkenyl aldehydes undergo a chiral thiiranium ion initiated cascade starting with intramolecular capture by a formyl group and termination by capture with HFIP solvent. This method provides a one-potsynthesis of dihydropyran and 1,3-disubstituted isochroman acetals in good to excellent
Cobalt-Catalyzed Cycloisomerization of 1,6-Enynes and Allyl Propargyl Ethers
作者:Alain Ajamian、James L. Gleason
DOI:10.1021/ol034541f
日期:2003.7.1
6-Enynes and allyl propargyl ethers undergo a cobalt-catalyzed formal 5-endo-dig cyclization to form vinyl cyclopentenes and dihydrofurans, respectively. The use of equimolar amounts of dicobalt octacarbonyl and trimethyl phosphite affords optimum yields and improved selectivity for cycloisomerization vs alkene isomerization.