Titanium-mediated [2 + 2 + 2] coupling of diynes with homoallylic alcohols.
[reaction: see text] In connection with the known diyne-ene [2 + 2 + 2] cycloaddition reactions mediated by titanium aryloxides, the ability of titanium alkoxides to promote coupling of a titanacyclopentadiene with an alkene has been assessed for the isomerization-free preparation of 1,3-cyclohexadienes. The successful cycloaddition by titanium alkoxides is predicated on the use of homoallylic alcohols as the olefin component. With secondary homoallylic alcohols, high 1,3-diastereoselectivity is observed, which lends itself to enantioselective preparation of functionalized 1,3-cyclohexadienes.
Sung
Moo Je
MJ
Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487, USA.
Pang
Jin-Hyun
JH
Park
Soon-Bong
SB
Cha
Jin Kun
JK
D000438:Alcohols / Q000138:chemical synthesis*; D000480:Alkynes / Q000737:chemistry*; D000498:Allyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D003521:Cyclopropanes / Q000737:chemistry; D006844:Hydrocarbons, Cyclic / Q000138:chemical synthesis; D009942:Organometallic Compounds / Q000737:chemistry; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry*
D000438:Alcohols; D000480:Alkynes; D000498:Allyl Compounds; D003521:Cyclopropanes; D006844:Hydrocarbons, Cyclic; D009942:Organometallic Compounds; D014025:Titanium