Soluble poly(ethylene glycol) (PEG)-supported telluride 2 was designed and synthesized for catalytic Wittig-type reactions. It was found that the catalytic loading could be reduced from 20 to 2 mol % by the introduction of PEG (even to 0.5 mol % when some telluride salts were used as the catalyst). Under the catalytic reaction conditions, a wide variety of aldehydes with different structures could
Soluble PEG-supported telluride 2 was synthesized and found to be an effective catalyst for the catalytic Wittig-typereaction to give a variety of α,β-unsaturated esters in high yields with excellent E-stereoselectivity in the presence of sodium bisulfite as well as triphenyl phosphite.
Chromatography-Free Wittig Reactions Using a Bifunctional Polymeric Reagent
作者:Peter Shu-Wai Leung、Yan Teng、Patrick H. Toy
DOI:10.1021/ol1021614
日期:2010.11.5
The first example of a polystyrene bearing two distinct reagent groups has been prepared. This phosphine and amine functionalized material was used in one-pot Wittig reactions with an aldehyde and either an α-halo-ester, -ketone, or -amide. Due to the heterogeneous nature of the polymer, the desired alkene product of these reactions could be isolated in excellent yield in essentially pure form after
The syntheses of four macrocyclic sperminealkaloids, (±)-budmunchiamine A – C (1a – c) and (±)-budmunchiamine L4 (1), were accomplished by Michael addition of spermine to the α,β-unsaturated esters 3a – d, followed by cyclization of the resulting α,ω-tetraamino esters 4a – d with triethoxyantimony; N-methylation of the amino lactams 6a – c yielded the budmunchiamines A – C (1a – c).
四种大环精胺生物碱 (±)-budmunchiamine A – C (1a – c) 和 (±)-budmunchiamine L4 (1) 的合成是通过 Michael 将精胺添加到 α,β-不饱和酯 3a – d 中完成的,然后用三乙氧基锑环化所得的 α,ω-四氨基酯 4a-d;氨基内酰胺 6a – c 的 N-甲基化产生 budmunchiamines A – C (1a – c)。
Total Synthesis of TK-57-164A, Isariotin F, and Their Putative Progenitor Isariotin E
作者:Jacob Y. Cha、Yaodong Huang、Thomas R. R. Pettus
DOI:10.1002/anie.200904716
日期:2009.12.7
Keeping it simple: A simple strategy for the totalsynthesis of three complex natural products has been developed, while also confirming the putative generation of 1 and 2 from 3. The benefits of a simple dissymmetric 2,5‐cyclohexadienone are illustrated and provide the foundation for rapid diastereoselective functionalization leading to the first totalsynthesis of these compounds.