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Development of Efficient Functionalization Using Organozirconium and Organoselenium Compouds

利用有机锆和有机硒化合物开发高效功能化

基本信息

批准号：
09650952
负责人：
SEGI Masahiko
金额：
$ 0.64万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

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.

有机锆化合物通过利用锆-碳键与各种亲电试剂的反应性可用于有机合成以得到所需的有机分子。另一方面，有机硒化学近年来成为有机合成中非常有力的工具。特别重要的是苯基硒基（PhSe）基团，由于其易于处理的性质。锆环戊烯（1）是由低价的锆茂化合物与炔发生偶联反应而制得。1与PhSeBr反应，然后质子猝灭，以良好的产率区域选择性地得到乙烯基硒醚。这些化合物通过硒氧化消除以良好的产率氧化得到相应的丙二烯衍生物。另一方面，用Cp_2ZrHCl（Schwartz试剂）对α位或β位带有苯硒基的末端炔进行锆氢化反应，区域选择性和立体选择性地得到了相应的末端乙烯基二茂锆衍生物。这些乙烯基锆化合物通过Zr-Cu金属转移反应与高级铜酸盐反应生成乙烯基铜酸盐中间体，在亲电试剂如烯酮、环氧化物或苄基溴的存在下，该中间体与它们进行有效的偶联反应，以良好的产率得到加合物。用过量的H2 O2氧化具有苯基硒基的加合物，分别通过[2，3] σ转移重排或硒氧化物顺式消除以高产率产生具有烯丙醇或F-形共轭二烯部分的所需产物。