选择环:叔丁基二甲基甲硅烷基叔丁基硫酸盐(TBSOTf)/ NEt 3处理与双环烷酮相连的炔基酯会形成三环烯酸酯,在环结处具有总的非对映选择性。涉及由TBSOTf / NEt 3双重激活促进的分子内的醇酸Mukaiyama aldol反应。(±)-hamigeran B的正式总合成说明了这种新颖的方法。
Enantioselective Conia-Ene-Type Cyclizations of Alkynyl Ketones through Cooperative Action of B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>, <i>N</i>-Alkylamine and a Zn-Based Catalyst
作者:Min Cao、Ahmet Yesilcimen、Masayuki Wasa
DOI:10.1021/jacs.8b13757
日期:2019.3.13
An efficient and highly enantioselective Conia-ene-type process has been developed. Reactions are catalyzed by a combination of B(C6F5)3, an N-alkylamine and a BOX-ZnI2 complex. Specifically, through cooperative action of B(C6F5)3 and amine, ketones with poorly acidic α-C-H bonds can be converted in situ to the corresponding enolates. Subsequent enantioselective cyclization involving a BOX-ZnI2-activated
Palladium-Catalyzed Enantioselective Cyclization of Silyloxy-1,6-Enynes
作者:Britton K. Corkey、F. Dean Toste
DOI:10.1021/ja068723r
日期:2007.3.1
Binaphane−Pd(II) complexes as catalysts for the formation of methylene cyclopentane adducts from 1,6-enyne precursors. The utility of this reaction is illustrated by its application to the totalsynthesis of the cytotoxic cyclolaurane-type sesquiterpene, (−)-laurebiphenyl.
Intramolecular Alkynylogous Mukaiyama Aldol Reaction Starting from Bicyclic Alkanones Tethered to Alkynyl Esters: Formal Total Synthesis of (±)-Hamigeran B
esters tethered to bicycloalkanones leads to the formation of tricyclic allenoates with total diasteroselectivity at the ring junction. An intramolecular alkynylogous Mukaiyama aldol reaction promoted by a TBSOTf/NEt3 dual activation is involved. This novel methodology was illustrated by a formaltotalsynthesis of (±)‐hamigeran B.
选择环:叔丁基二甲基甲硅烷基叔丁基硫酸盐(TBSOTf)/ NEt 3处理与双环烷酮相连的炔基酯会形成三环烯酸酯,在环结处具有总的非对映选择性。涉及由TBSOTf / NEt 3双重激活促进的分子内的醇酸Mukaiyama aldol反应。(±)-hamigeran B的正式总合成说明了这种新颖的方法。
Intramolecular Schmidt Reaction of Vinyl Azides with Cyclic Ketones
tethered with a vinyl azide group undergo a Schmidt-hydrolysis sequence to give secondary lactams bearing a ketone side chain. Secondary lactams are obtained in a regioselective manner that is not possible in a conventional Schimdt reaction. In addition to the well-documented C-2 nucleophilicity, the N nucleophilicity of vinyl azide disclosed in this work opens a new direction for reaction invention involving