(R)-乙基-2-吡啶亚砜与(4R,5R)-TADDOL包结晶体 [C7H9NOS·C31H30O4]的晶体结构分析

（Ｒ）－乙基－２－吡啶亚砜与（４Ｒ，５Ｒ）－二（羟基－二苯基－甲基）－２，２－二甲基－１，３－二氧戊环（ＴＡＤ－ＤＯＬ）可以形成物质的量比为１∶１的手性包结晶体，Ｘ射线衍射分析确定该晶体属单钭晶系，Ｐ２１空间群，ａ＝０．９７０１（２）ｎｍ，ｂ＝０．９９５３（２）ｎｍ，ｃ＝１．７３９２（２）ｎｍ；β＝９２．０７９°（１４），Ｖ＝１．６７８１（５）ｎｍ３，Ｚ＝２，Ｄｃ＝１．２３０ｇ／ｃｍ３，分子式Ｃ３８Ｈ３９ＮＯ５Ｓ，Ｍｒ＝６２１．７６，最终偏离因子Ｒ＝０．０３５１，ＲＷ２＝０．０７７２，Ｆｌａｃｋ值为０．１（２）．结构分析表明，主客体存在分子间氢键．光学纯的ＴＡＤＤＯＬ与消旋的乙基吡啶亚砜（１）作用时，ＴＡＤＤＯＬ对１具有很好的手性识别能力，选择性地与１的一个对映体形成氢键，长成晶体．参照晶体结构确定了１的两个对映体的绝对构型     

Ni‐Catalyzed Asymmetric Cycloisomerization of Dienes by Using TADDOL Phosphoramidites

A library of α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol (TADDOL)‐based phosphoramidites has been synthesized and applied in the Ni‐catalyzed cycloisomerization of different dienes. Through the systematic variation of the three structural motifs of the lead structure, that is, the amine moiety, the protecting group, and the aryl substituents, the ligand features could be optimized for the asymmetric cycloisomerization of the model substrate diethyl diallylmalonate. The substrate scope of the new catalytic system was extended to other diallylic substrates, including unsymmetrical dienes. Overall remarkably high activities of up to approximately 13 500 h^?1, very high selectivities toward five‐membered exo‐methylenecyclopentanes, and enantioselectivities of up to 92 % ee have been achieved.     

Preparation and Characterization of New C2‐ and C1‐Symmetric Nitrogen,Oxygen, Phosphorous,and Sulfur Derivatives and Analogs of TADDOL. Part II

TADDOL (=α,α,α′,α′‐Tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol) and the corresponding dichloride are converted to TADDAMINs (=(4S,5S)‐2,2,N,N′‐tetramethyl‐α,α,α′,α′‐tetraphenyl‐1,3‐dioxolan‐4,5‐dimethanamines) (Scheme 2) and ureas, 12 – 15 , and to TADDOP derivatives with seven‐membered O? P? O ester rings (Schemes 3 and 4). Cl/P‐Replacement via the Michaelis? Arbuzov reaction (Scheme 7) on mono‐ and dichlorides, derived from TADDOL, are described. It was not possible to obtain phosphines with the P‐atom attached to the benzhydrylic C‐atom of the TADDOL skeleton (Schemes 6 and 7). The X‐ray crystal structures (Figs. 1 and 2) of ten of the more than 30 new TADDOL derivatives are discussed. Full experimental details are presented.     

In silico correlation of enantioselectivity for the TADDOL catalyzed asymmetric hetero-Diels-Alder reaction

The reverse-docking of a TADDOL organocatalyst to rigid transition state models of catalyst-free reactions (TS-models) for an asymmetric hetero-Diels-Alder reaction is described. In previous reports, reverse-docking of similar organocatalysts to rigid TS-models showed promise for generating transition state models for the catalyzed reaction, and revealed clear energetic trends favoring the experimentally preferred product enantiomers. Although results indicated a mode of catalysis consistent with experimental data, relative docking energies between TS-model enantiomers were too great to allow for in silico correlation to experimentally observed enantiomeric excesses (ee). Several changes were made to the reverse-docking algorithm, EM-Dock, allowing for the first reported correlation to experimentally reported ee values based solely on reverse-docking and molecular mechanics energies.