Development of Efficient Functionalization Using Organozirconium and Organoselenium Compouds

有机锆化合物可用于有机合成，利用01锆-碳键与各种亲电试剂的反应性得到所需的有机分子。另一方面，近年来有机硒化学成为有机合成的有力工具。特别重要的是苯硒（PhSe）基团，因为它易于处理。该基团最常见和最有用的转化之一是氧化去除，分别通过硒氧化物消除或[2,3]异位重排生成烯烃或烯丙醇。锆环戊烯(1)是由低价锆新世与炔烃偶联反应制备的。1与PhSeBr反应后进行质子猝灭，得到了收率较高的乙烯基硒化物。这些化合物通过硒氧化物消除被氧化得到相应的高产量的烯衍生物。另一方面，用Cp2ZrHCI （Schwartz试剂）对α或β位置有苯基硒基的端炔进行氢锆化反应，得到相应的端乙烯基锆新世区域和立体选择性衍生物。这些乙烯基锆化合物与高阶铜酸盐通过Zr-Cu转金属反应生成乙烯基铜酸盐中间体，这些中间体在烯酮、环氧化物或苄溴等亲电试剂的存在下，与它们进行了有效的偶联反应，得到了产率较高的加合物。含苯基硒基的加合物用过量的H202氧化，分别通过[2,3]异位重排或硒酸盐合成消除得到高产量的烯丙醇或f形共轭二烯部分的所需产物。

Organozirconium compounds are useful for organic synthesis by utilizing the reactivity 01 zirconium-carbon bond with a variety of electrophilic reagents to give desired organic molecules. On the other hand, organoselenium chemistry became a very powerful tool in organic synthesis in recent times. Of perticular importance is the phenylseleno (PhSe) group owing to its easily handled nature. One of the most common and useful transformations of this group is its oxidative removal leading to olefins or allylic alcohols via selenoxide elimination or [2,3] sigmatropic rearrangement, respectively.Zirconacyclopentenes (1) are easily prepared by coupling reaction of a low valent zirconocene with alkynes. The reaction of 1 with PhSeBr followed by proton quenching gave vinylselenides in good yields regioselectively. These compounds were oxidized to give the corresponding allene derivatives in good yields via selenoxide elimination. On the other hand, hydrozirconation of terminal alkynes having a phenylseleno group at alpha or beta position with Cp2ZrHCI (Schwartz reagent) gave the corresponding terminal vinylzirconocene derivatives regio- and stereoselectively. These vinylzirconium compounds reacted with a higher order cuprate to generate vinylcuprate intermediates via Zr-Cu transmetalation, which in the presence of electrophiles such as enones, epoxides, or benzyl bromide underwent the coupling reaction with them effectively to afford the adducts in good yields. The adducts with a phenylseleno group were oxidized with excess amounts of H202 to yield the desired products having allylic alcohol or F-shaped conjugated diene moiety in high yields via [2,3] sigmatropic rearrangement or selenoxide syn elimination, respectively.