The consequences of strain release in the norbornyl subunit of isodicyclopentadiene on cycloaddition stereochemistry. Further evidence that orbital tilting serves as the key determinant of contrasteric π-facial selectivity
作者:Leo A. Paquette、Eugene R. Hickey
DOI:10.1016/0040-4039(94)85207-3
日期:1994.4
Diels-Alder cycloadditions to 2 and 3 occur preferentially from the top face in contra-distinction to the behavior of isodicyclopentadiene (1). This reversal in facial stereoselectivity is shown not to arise from torsional constraints, but to be consistent with the overriding of stericeffects by orbital tilting in 1.
The Role of [η
<sup>2</sup>
‐Bis(
<i>tert</i>
‐butylsulfonyl)acetylene](carbonyl)(η
<sup>5</sup>
‐cyclopentadienyl)cobalt(
<scp>I</scp>
) as an Intermediate in the Alkyne Dimerisation
作者:Tobias H. Staeb、Jorge Chávez、Rolf Gleiter、Bernhard Nuber
Alkyne Dicobalt Carbonyl Complexes with Sulfide Ligands. Synthesis, Crystal Structure, and Dynamic Behavior
作者:Xavier Verdaguer、Albert Moyano、Miquel A. Pericàs、Antoni Riera、Angel Alvarez-Larena、Joan-F. Piniella
DOI:10.1021/om9903036
日期:1999.10.1
reacts with 3 to generate a chiral sulfide complex 8 (58%). The solid-state structures of 5 and 8 have been established by X-ray crystallography and reveal the preference of the incoming sulfur ligand to occupy an equatorial coordination site. Further structural studies on 5 have been performed by low-temperature 1H NMR analysis and by theoretical procedures at the PM3(tm) level of theory. Analysis
六羰基二钴复合的双(叔-butylsulfonylethyne)[CO 2(μ-卜吨SO 2 C)2(CO)6,3 ]经历与甲基热诱导的配体交换过程p -甲苯基硫醚,二苄基硫醚,和二乙基硫醚以得到相应的稳定硫化物络合物[CO 2(μ-卜吨SO 2 C)2(CO)5 SR 2 ] 4,5,和6,分别以高产(59−65%)。与四氢噻吩的反应以74%的产率得到二取代的配合物7。衍生自(+)-(2 R)-10-巯基异冰片醇的Oxathiane 9也与3反应生成手性硫化物络合物8(58%)。通过X射线晶体学已经确定了5和8的固态结构,并揭示了进入的硫配体占据赤道配位位点的偏好。通过低温1 H NMR分析和在理论上PM3(tm)上的理论程序,对5进行了进一步的结构研究。低温分析1个的1 H NMR光谱5示出了信号分离器具有两个平展协调硫化物之间的平衡的冻结,以及不同的异构体的计算研究结果一致5示出了个平展配位的络合物为3
Twofold bridged sulfone-substituted Dewar–Benzenes: new ways to twofold bridged prismanes
作者:Rolf Gleiter、Frank Ohlbach
DOI:10.1039/c39940002049
日期:——
The di(tert-butylsulfonyl) substituents in the 2,3-positions of doubly bridged Dewar benzenes have been replaced by alkyl or aryl substituents; the resulting Dewar benzenes have been transformed to the corresponding prismanes.
5-dihydro-1H-thieno[3,4-c]pyrrole 2,2-dioxides 3, have been prepared by the oxidation of their corresponding pyrroline derivatives 4 with DDQ or Chemical MnO2. The Diels-Alder reaction of 3 with dimethyl acetylenedicarboxylate gave new types of compunds: 7-aza-2,3-dimethylenenorbornenes A, the 1:2 adducts B, 1a,3a,6,9-tetrahydrobenz[g]indoles C, and dihydroindolosulfolene D depending on the reaction conditions and the
通过用DDQ或化学MnO 2氧化相应的吡咯啉衍生物4,可以制备新的结构单元3,5-二氢-1 H-噻吩并[3,4- c ]吡咯2,2-二氧化物3。3与乙酰二羧酸二甲酯的Diels-Alder反应产生了新的化合物:7-氮杂-2,3-二亚甲基降冰片烯A,1:2加合物B,1a,3a,6,9-四氢苯并[ g ]吲哚C和dihydroindolosulfolene d取决于反应条件和ñ -取代基。3与二(叔)的反应还描述了-丁基磺酰基)乙炔。