Efficient preparation of trisubstituted alkenes using the SmI2 modification of the Julia–Lythgoe olefination of ketones and aldehydes
作者:István E Markó、Fiona Murphy、Lucien Kumps、Ali Ates、Roland Touillaux、Donald Craig、Santiago Carballares、Simon Dolan
DOI:10.1016/s0040-4020(01)00079-5
日期:2001.3
High yields of di- and tri-substituted alkenes are obtained by a modification of the Julia–Lythgoeolefination reaction involving the in situ capture of intermediate β-alkoxy-sulfones by benzoyl or trimethylsilyl chloride, followed by SmI2-mediated reductiveelimination. This novel protocol also provides a connective preparation of dienyl ethers, which are important partners in Diels–Alder cycloadditions
Synthesis of alkenes with P-(α-lithioalkyl)phosphinothioic amides
作者:Carl R. Johnson、Robert C. Elliott
DOI:10.1021/ja00389a026
日期:1982.12
Reactions of 1,1-dihaloalkenes with triorganozincates: a novel method for the preparation of alkenylzinc species associated with carbon-carbon bond formation
Lithium trialkylzincates react with 1,1-dibromoalkenes 1 and 1-bromo-1-chloroalkenes 2 at -85-degrees-C in THF to give 1-bromoalkenes 5 and 1-chloroalkenes 7, respectively, upon hydrolysis. The intermediate (1-haloalkenyl)zincates 4 and 6 are stable at low temperature but, when allowed to warm to 0-degrees-C, they undergo a 1,2-alkyl migration reaction to afford alkenylzinc species 10. A variety of alkylation products 11 are obtained by the hydrolysis of 10. In the presence of (Ph3P)2Pd (5 mol%), alkenylzinc species 10 react smoothly with organic halides (AcCl, EtOCOCl, CH2=CH-(Me)Br, PhBr) to yield the corresponding coupling products 13-16.
JOHNSON, C. R.;ELLIOTT, R. C., J. AMER. CHEM. SOC., 1982, 104, N 25, 7041-7044
作者:JOHNSON, C. R.、ELLIOTT, R. C.
DOI:——
日期:——
HARADA, TOSHIRO;HARA, DAIJI;HATTORI, KAZUHIRO;OKU, AKIRA, TETRAHEDRON LETT., 29,(1988) N 31, C. 3821-3824