A Highly Efficient Synthesis of (−)-PI-091 Construction of the 4-Alkoxy-2-butene-4-lactam Skeleton from Fischer-Type Carbene Complexes, Alkynyllithiums, and Tosyl Isocyanate
A Highly Efficient Synthesis of (−)-PI-091 Construction of the 4-Alkoxy-2-butene-4-lactam Skeleton from Fischer-Type Carbene Complexes, Alkynyllithiums, and Tosyl Isocyanate
Stereoselective syntheses of substituted enynes, dienes, and alkenes via stannylation of 1-trimethylsilyl 1,3-diynes
作者:George Zweifel、William Leong
DOI:10.1021/ja00255a029
日期:1987.10
ZWEIFEL, GEORGE;LEONG, WILLIAM, J. AMER. CHEM. SOC., 109,(1987) N 21, 6409-6412
作者:ZWEIFEL, GEORGE、LEONG, WILLIAM
DOI:——
日期:——
Dimethylzinc-Mediated Additions of Alkenylzirconocenes to Aldimines. New Methodologies for Allylic Amine and <i>C</i>-Cyclopropylalkylamine Syntheses
作者:Peter Wipf、Christopher Kendall、Corey R. J. Stephenson
DOI:10.1021/ja028092a
日期:2003.1.1
Hydrozirconation of alkynes with zirconocene hydrochloride followed by in situ transmetalation to dimethylzinc provides access to reactive alkenyl organometallic reagents from readily available precursors. Upon addition of imines, 1,2-attack leads to synthetically useful allylic amine building blocks. In the presence of CH2I2 or CH2Cl2, the N-metalated allylic amide intermediate is cyclopropanated and C-cyclopropylalkylamines are formed in high yield and excellent diastereoselectivities favoring the anti products. The use of enynes as starting materials for this domino reaction provides conjugated biscyclopropanes and thus allows the stereoselective formation of five new carbon-carbon bonds. A transition state that explains the need for both zirconocene complex and alkyl zinc in the cyclopropanation reaction is proposed.
A Highly Efficient Synthesis of (−)-PI-091 Construction of the 4-Alkoxy-2-butene-4-lactam Skeleton from Fischer-Type Carbene Complexes, Alkynyllithiums, and Tosyl Isocyanate