Magnesiated Unsaturated Silylated Cyanohydrins as Synthetic Equivalents of Aromatic and Heterocyclic Grignard Reagents Bearing a Ketone or an Aldehyde
作者:Ching-Yuan Liu、Hongjun Ren、Paul Knochel
DOI:10.1021/ol052792d
日期:2006.2.1
[reaction: see text] The preparation of iodo-substituted aryl, heteroaryl, or cycloalkenyl ketones as silylated cyanohydrins allows the smooth performance of an I/Mg-exchange using i-PrMgCl.LiCl. A facile deprotection of the resulting functionalized products obtained by a reaction with electrophiles (acid chlorides, allylicbromide, benzylidene-p-toluenesulfonamide, and 3-iodocyclohexenone) produces
Palladium-Catalyzed Ullmann Cross-Coupling of β-Iodoenones and β-Iodoacrylates with <i>o</i>-Halonitroarenes or <i>o</i>-Iodobenzonitriles and Reductive Cyclization of the Resulting Products To Give Diverse Heterocyclic Systems
作者:Faiyaz Khan、Michael Dlugosch、Xin Liu、Marium Khan、Martin G. Banwell、Jas S. Ward、Paul D. Carr
DOI:10.1021/acs.orglett.8b01015
日期:2018.5.4
palladium-catalyzed Ullmann cross-coupling of β-iodoenones and β-iodoacrylates such as 5 (X = I) with o-halonitroarenes and o-iodobenzonitriles including 2 affords products such as compound7. These can be engaged in a range of reductive cyclization reactions leading to heterocyclic frameworks such as 3,4-benzomorphan derivative 43.
Photo-reaction of .BETA.-ketovinyl sulfur compounds.
作者:YASUMITSU TAMURA、HIROSHI KIYOKAWA、YASUYUKI KITA
DOI:10.1248/cpb.27.676
日期:——
Photolysis of mono-and di-β-ketovinyl sulfones in benzene solution caused an extrusion of sulfur dioxide to give the corresponding β-phenyl enone and bis-enones in moderate yields, respectively, and that of di-β-ketovinyl sulfide and sulfoxide was also examined.
Intermolecular homocoupling of alkenyltrimethylstannane functions mediated by CuCl: Preparation of functionalized conjugated diene and tetraene systems
作者:Edward Piers、Patricia L. Gladstone、James G.K. Yee、Ernest J. McEachern
DOI:10.1016/s0040-4020(98)00592-4
日期:1998.9
substrates containing an alkenyltrimethylstannane function are reported. Thus, treatment of each of the stannanes 1–15 with 2.5 equivalents of CuCl in N,N-dimethylformamide (DMF) provides the corresponding dienes or tetraenes 16–32.
Preparation and reactivity of functionalized alkenyl-zinc, -copper, and -chromium organometallics
作者:Paul Knochel、C. Janakiram Rao
DOI:10.1016/s0040-4020(01)80504-4
日期:1993.1
Beta-halogeno-alpha,beta-unsaturated carbonyl derivatives were converted to the corresponding zinc organometallics 2a under mild conditions in THF (Zn dust, 25-45-degrees-C, 1-4h). These functionalized alkenylzinc iodides react with a variety of alkenyl and aromatic iodides affording the desired coupling products in 40-97% yield. The addition of a THF solution of CuCN.2LiCl to 2a affords the corresponding organocopper derivatives 2b which react with electrophiles, such as alkynyl and allylic halides, nitro olefins, enones, and chlorotrimethylstannane providing polyfunctional unsaturated carbonyl compounds in 71-95% yield. The insertion of chromium (II) chloride to beta-iodo and to some beta-(p-tosyl)enones in DMF furnishes new functionalized chromium (III) organometallics 2c which react with aldehydes providing gamma-hydroxy unsaturated carbonyl derivatives in 40-91% yield. The synthetic scope and the limitations of this methodology are discussed.