1989 Fiscal Year Final Research Report Summary
New Method of Radical Formation and Its Application to Organic Synthesis
| Project/Area Number |
63470074
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
有機工業化学
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
UTIMOTO Kiitiro Kyoto Univ., Fac. Eng., Professor, 工学部, 教授 (90025958)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MATSUBARA Seijiro Kyoto Univ., Fac. Eng., Instructor, 工学部, 助手 (90190496)
OSHIMA Koichiro Kyoto Univ., Fac. Eng., Assoc. Professor, 工学部, 助教授 (00111922)
|
|---|
| Project Period (FY) |
1988 – 1989
|
| Keywords | Radical / Triethylborane / Triphenystannane / Addition / Cyclization / Triphenylgermane / Acetylene / Alkyl iodide |
|---|
| Research Abstract |
Novel efficient method for the generation of organic radical species has been applied to organic syntheses. Triethylborane-initiated addition of triphenylstannane to acetylenes proceeds smoothly in high regio- and stereoselectivity. Application to an acetylene containing an olefinic bond at appropriate position provides a cyclized product stereoselectively; triphenyltin radical attacks at acetylene bond regioselectively to give a vinyl radical, which adds intramolecularly to an olefin stereoselectively. Triphenylgermane adds to a 1-alkyne under triethylborane catalysis. In this case, reaction is kinetically controlled at -78ﾟC to give Z-isomer, whereas reaction is thermodynamically controlled at 60ﾟC affording Enisomer predominantly. By the mechanistic investigation of the above reaction, an efficient procedure of the isomerization of olefin geometry has been devised. Alkyl halides can be reduced to the corresponding hydrocarbons by radical type reduction. Intramolecular addition of alkoxythiocarbonyl radical, an acyl radical equivalent, gives an -methylene lactone. Alkyl iodides add to acetylene smoothly under triethylborane catalysis to give vinyl iodides regio- and stereoselectively. Perfluoroalkyl iodides add to acetylenes analogously. Reaction of an -bromo ketone with a carbonyl compound in the presence of triethylborane gives a Reformatsky type reaction product; formation of boron enolate and reaction with aldehyde to give an aldol product. Triethylborane-mediated addition of an alkyl iodide to methyl vinyl ketone also gives a boron enolate. As the obtained boron enolate reacts with an aldehyde to give aldol product, the above reactions opens novel three components coupling reaction of alkyl iodide, methyl vinyl ketone, and aldehyde.
|
