A new synthesis of 1,5-dicarbonyl compounds under neutral conditions
作者:Noboru Ono、Hideyoshi Miyake、Aritsune Kaji
DOI:10.1039/c39830000875
日期:——
Michael addition of α-nitroketones to methyl vinyl ketone or acrylaldehyde followed by denitration with Bu3SnH affords 1,5-dicarbonylcompounds in good yields.
The invention relates to novel cyclopenteno[b]pyridine derivatives which have a group X on the 7-position and related tricyclic compounds. X is CONHR.sup.3, or CO.sub.2 R.sup.5 wherein R.sup.3 is hydrogen or lower alkyl and R.sup.5 is hydrogen or a lower alkyl or lower aralkyl group which may be substituted by alkyl, alkoxy, halogen, nitro or trifluoromethyl; other substituents may be present. The compounds are intermediates for compounds wherein X is CSNHR.sup.3 which are anti-ulcer agents.
Dityltin bis(triflate) is a mild Lewisacid which catalyzes clean Michael addition of enol silylethers. The new catalyst allows to employ various labile acceptors such as methyl vinyl ketone and 2-cyclopentenone which do not undergo smooth reaction with conventional Lewisacids. A variety of enol silylethers are also employable and thus 2-(trimethylsiloxy)propene, the simplest one in this class of
Surface-mediated solid phase reaction. Mukaiyama-Michael addition of silyl enol ethers to methyl vinyl ketone on the surface of alumina
作者:Brindaban C. Ranu、Manika Saha、Sanjay Bhar
DOI:10.1016/s0040-4039(00)91983-x
日期:1993.3
Clean and efficient Michael addition of silyl enol ethers to methyl vinyl ketone has been achieved through a simple solvent-free reaction on the surfac
and Michael reactions of silyl enol ethers with carbonyl compounds or other electrophiles (trimethyl orthoformate, dimethyl acetal, and chloromethyl methyl ether), the allylation reaction of allylsilanes with aldehydes, and the Diels–Alder reaction of dienes with α,β-unsaturated aldehydes. A solution of formaldehyde in water is applicable as an electrophile. Also, the aldol-type reaction of ketene silyl