Studies on Cu(I)-catalyzed synthesis of simple 3-substituted 1,2-allenes and optically active 2-substituted secondary 2,3-allenols
作者:Jing Li、Chao Zhou、Chunling Fu、Shengming Ma
DOI:10.1016/j.tet.2009.02.061
日期:2009.5
methyl ethers, which would react with primary alkyl Grignard reagents under the catalysis of CuBr to afford 3-substituted 1,2-allenes or 2-substituted secondary 2,3-allenols, respectively. The reaction may be applied to the synthesis of optically active 2-substituted secondary 2,3-allenols with up to >99% ee without any protection to the free hydroxyl group in the starting 4-hydroxy-2-alkynyl methyl
One, two, three, four: A copper(I)–phosphine complex catalyzes the diborylation of alkynes and arynes, and the tri‐ or tetraborylation of propargyl ethers (see scheme; pin=pinacolato). In the latter cases, the CO bond(s) as well as the CC bond are borylated in one pot. Furthermore, a diborylation product serves as an intermediate in the efficient synthesis of ortho‐terphenyls with pharmacological
The direct addition of in situgenerated hydrazoic acid to alkynes is realized without solvent by using a gold catalyst derived from a recently designed remotely functionalized biaryl-2-ylphosphine ligand (i.e., WangPhos). With terminal alkynes, the additions are mostly realized with 0.1 mol% catalyst loadings and at 40 °C. With more challenging internal alkynes devoid of direct EWG substitution, the
Dimethylaluminum halide induced reactions of formaldehyde with alkynes. Synthesis of α-allenic alcohols and Z-3-chloroallylic alcohols
作者:David J. Rodini、Barry B. Snider
DOI:10.1016/0040-4039(80)80199-7
日期:1980.1
The CH2O·Me2AlCl complex reacts with terminal alkynes to give α-allenicalcohols via a formal ene reaction and Z-3-chloroallylicalcohols via a stereospecifically syn Friedel-Crafts addition.
Treatment of homopropargylic alcohol derivatives or phenylacetylene compounds with phenylmagnesium bromide in the presence of a catalytic amount of manganese(II) chloride afforded phenylated products in good yields with high regio- and stereoselectivities.
在催化量的氯化锰 (II) 存在下,用溴化苯基镁处理高炔丙醇衍生物或苯乙炔化合物,以高产率和高区域选择性和立体选择性提供苯化产物。