Arrayás Ramón Gómez, Yin Jingjun, Liebeskind Lanny S
Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, USA.
J Am Chem Soc. 2007 Feb 14;129(6):1816-25. doi: 10.1021/ja067104f.
TpMo(CO)2(5-alkenyl-eta-2,3,4-pyranyl) diene complexes function as excellent chiral scaffolds for the efficient regio- and enantiocontrolled synthesis of highly functionalized 1-oxadecaline derivatives through a novel transition metal-mediated Diels-Alder reaction. Very good to excellent yields and excellent levels of endo selectivity are obtained, and the reaction gives products with complete retention of enantiomeric purity when carried out with chiral, nonracemic scaffolds. A subtle structural modification on the diene (replacement of an H by a trans-CH3 group) leads to a complete change of regiochemistry, which is discussed from a mechanistic point of view. The role of the eta3-coordinated TpMo(CO)2 moiety is also critical to the further functionalization of the [4 + 2] cycloadducts, as illustrated by the preparation of 20 variously functionalized 1-oxadecaline derivatives (>98% ee when carried out with high enantiopurity scaffolds).
二羰基（5-烯基-η-2,3,4-吡喃基）钼二烯配合物作为优良的手性骨架，通过新型过渡金属介导的狄尔斯-阿尔德反应，能够高效地实现区域和对映体控制的高度官能化1-氧杂萘满衍生物的合成。反应能获得非常好至优异的产率以及优异的内型选择性，并且当使用手性、非外消旋骨架进行反应时，产物的对映体纯度能够完全保持。二烯上一个细微的结构修饰（用反式-CH3基团取代一个H）会导致区域化学的完全改变，本文将从机理角度对此进行讨论。η3配位的TpMo(CO)2部分对于[4 + 2]环加成产物的进一步官能化也至关重要，这一点通过制备20种不同官能化的1-氧杂萘满衍生物得到了证明（使用高对映体纯度的骨架进行反应时，对映体过量>98%）。
