Synthesis and Application of Substituted 1,16-Dihydroxytetraphenylenes in Catalytic Asymmetric Allylboration of Ketones
作者:Guo-Li Chai、Bo Zhu、Junbiao Chang
DOI:10.1021/acs.joc.8b02475
日期:2019.1.4
The synthesis and application of a newly designed C2-symmetric chiral-substituted 1,16-dihedroxytetraphenylene (DHTP) is reported. Efficient syntheses of enantiopure substituted DHTP were accomplished, and these enantiopure compounds were used as organocatalysts in asymmetric allylboration of ketones under very mild conditions. Accordingly, several tertiary alcohols were generated in moderate to good
Asymmetric Allylboration of Ketones Catalyzed by Chiral Diols
作者:Sha Lou、Philip N. Moquist、Scott E. Schaus
DOI:10.1021/ja0651308
日期:2006.10.1
Chiral BINOL-derived diols catalyze the enantioselective asymmetricallylboration of ketones. The reaction requires 15 mol % of 3,3‘-Br2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (76−93%) and high enantiomeric ratios (95:5−99.5:0.5). High diastereoselectivities (dr ≥ 98:2) and enantioselectivities (er ≥ 98:2) are obtained
Catalytic Asymmetric Allylation of Ketones and a Tandem Asymmetric Allylation/Diastereoselective Epoxidation of Cyclic Enones
作者:Jeung Gon Kim、Karen M. Waltz、Iliana F. Garcia、David Kwiatkowski、Patrick J. Walsh
DOI:10.1021/ja047758t
日期:2004.10.1
titanium tetraisopropoxide, BINOL, 2-propanol additive, and tetraallylstannane as allylating agent. A variety of ketone substrates, including acetophenone derivatives and alpha,beta-unsaturated cyclic enones, reacted to form tertiary homoallylic alcohols in good yields (67-99%) and with high levels of enantioselectivity (generally >80%). A novel one-pot enantioselective allylation/diastereoselective
Rhodium-Catalyzed Kinetic Resolution of Tertiary Homoallyl Alcohols via Stereoselective Carbon−Carbon Bond Cleavage
作者:Ryo Shintani、Keishi Takatsu、Tamio Hayashi
DOI:10.1021/ol800120p
日期:2008.3.1
A nonenzymatic kinetic resolution of tertiary homoallyl alcohols has been developed through a rhodium-catalyzed retro-allylation reaction under simple conditions. Selectivity factors of up to 12 have been achieved by employing (R)-H8-binap as the ligand, and the reaction can be conducted on a preparative scale.
The first example of catalyticenantioselective allylboration and crotylboration of simple ketones is described. High enantioselectivity (up to 93% ee) was obtained using 3 mol % CuF-iPr-DuPHOS as a chiral catalyst and 4.5 mol % La(OiPr)3 as a cocatalyst. Mechanistic studies strongly suggested that the active nucleophile of the present reaction is an allylcopper, and that La(OiPr)3 facilitates the