四烷氧基钛和酒石酸二烷基酯的等摩尔混合物中的主要物质显示为[Ti(酒石酸盐)(OR) 2 ] 2 ,它被确定为叔烷基氢过氧化物对烯丙醇不对称环氧化的活性催化剂。该物种的溶液相结构与先前报道的酒石酰胺钛配合物的 X 射线结构测定结果一致,如通过 IR 和 1 H、 13 C 和 17 O NMR 光谱分析。报告了钛 (IV) 醇盐和烷基过氧化物配合物的前 17 O NMR 光谱,以及对不对称环氧化反应的二次氘同位素效应研究的结果。提出了关于不对称环氧化机制的一般结论
Lithium borohydride reduction of 2,3-epoxyalcohols was shown to yield 1,2-diols in high regioselectivity with the aid of titanium tetraisopropoxide in benzene solution.
Mechanism of asymmetric epoxidation. 2. Catalyst structure
作者:M. G. Finn、K. Barry Sharpless
DOI:10.1021/ja00001a019
日期:1991.1
equimolar mixtures of titanium tetraalkoxides and dialkyl tartrate esters is shown to be [Ti(tartrate)(OR) 2 ] 2 , which is identified as the active catalyst for asymmetric epoxidation of allylic alcohols by tertiary alkyl hydroperoxides. The solution-phase structure of this species is consistent with the results on an X-ray structural determination of a titanium tartramide complex reported previously, as
四烷氧基钛和酒石酸二烷基酯的等摩尔混合物中的主要物质显示为[Ti(酒石酸盐)(OR) 2 ] 2 ,它被确定为叔烷基氢过氧化物对烯丙醇不对称环氧化的活性催化剂。该物种的溶液相结构与先前报道的酒石酰胺钛配合物的 X 射线结构测定结果一致,如通过 IR 和 1 H、 13 C 和 17 O NMR 光谱分析。报告了钛 (IV) 醇盐和烷基过氧化物配合物的前 17 O NMR 光谱,以及对不对称环氧化反应的二次氘同位素效应研究的结果。提出了关于不对称环氧化机制的一般结论
Regioselective reductions of 2,3-epoxy alcohols
作者:Steven M. Viti
DOI:10.1016/s0040-4039(00)85648-8
日期:1982.1
Regioselective reduction of 3-substituted-2,3-epoxy alcohols to 1,3-diols with sodiumbis(2-methoxyethoxy)aluminumhydride (Red-al) is shown to be a general reaction for these substitutes.
A convergent and efficient preparation method of the photoaffinity 3-(4-alkoxyphenyl)-3-trifluoromethyldiazirine derivatives was established by direct introduction of the photoaffinity group utilizing the Mitsunobu reaction.
Modified ethylene-vinyl alcohol copolymer and method for the production thereof
申请人:——
公开号:US20040096683A1
公开(公告)日:2004-05-20
Provided is a modified ethylene-vinyl alcohol copolymer (C) having an ethylen content of 5 to 55 mol %, which contains a specific structural unit (I) in an amount of 0.3 to 40 mol % and may be obtained by reacting an ethylene-vinyl alcohol copolymer (A) with a monofunctional epoxy compound (B) having a molecular weight of not more than 500. This can be produced by a method for producing the modified ethylene-vinyl alcohol copolymer (C) which comprises melting and kneading an ethylene-vinyl alcohol copolymer (A) with a monofunctional epoxy compound (B) in an extruder. The modified ethylene-vinyl alcohol copolymer (C) is superior to a unmodified ethylene-vinyl alcohol copolymer (A) in transparency, stretchability, flexibility and flexing resistance due to the specific structural unit (I) incorporated therein, and thus, can be used as a barrier material in various applications requiring the above performance capabilities.