Synthesis of Biologically Active Compounds Using Potential Utility of Transition Metals

(1)Sm(II)碘催化芳环上的螺环化反应。在有机合成中，Sm(II)试剂的还原和碳碳键的形成引起了人们的极大兴趣。相比之下，Sm(II)在芳香环上的自由基环化反应一直是前所未有的，直到最近。2000年，我们发现Sm(II)能有效地促进芳香族甲氧基的自由基IPSO取代，从而得到环化产物。在这些结果的基础上，从苯甲酸酯在酯基(化学)的对位上具有氧代烷基团开始，实现了芳环上的自由基螺环反应。交警。2002,316)(2)钯催化亚磺基锌的研究进展。亚硫基阴离子是合成各种亚硫基化合物的重要反应中间体。首次发现在Pd(0)催化剂(Org.)存在下，Et_2ZN处理1-炔基硫代硫醚可生成亚硫基锌物种。2001年，3,3627)。由于该方法在非常温和的反应条件下容易生成，因此能够立体选择性地合成各种官能化的乙烯基硫氧化物。(3)一种新颖的钯催化反应合成氨基烯。近年来，氨基联烯引起了人们的极大兴趣，因为它们是构建各种氮杂环的多功能底物。我们发现了一种使用钯(0)/二乙基锌体系合成包括氨基烯在内的联烯的通用而有效的方法：用二乙基锌和钯(0)催化剂处理2溴2烯1醇的甲磺酸酯或三氯乙酸酯，得到各种含有氨基烷基、烷基或芳基取代基的联烯，产率从好到高(J.Org，Chem)。2002年、67、1359)

(1) Samarium(II) IodideMediated Spirocyclization onto an Aromatic Ring. Both the reduction and carboncarbon bond formation with samarium(II) reagents have attracted much interest in organic synthesis. In contrast, samarium(II) mediated radical cyclization onto an arene ring had been unprecedented until recently. In 2000, we found that a radical ipso substitution of the aromatic methoxy group is effectively promoted by samarium(II) to afford the cyclized products. Based on these results, the radical spirocyclization onto an aromatic ring have been realized starting from benzoate possessing an oxoalkyl group at the para position to the ester group (Chem. Commun. 2002, 316)(2) Development of PalladiumCatalyzed Sulfinylzincation. Sulfinyl anion is an important reaction intermediate to synthesize various sulfinyl compounds. We have firstly found that sulfinylzinc species can be generated upon treatment of 1 alkynyl suifoxides with Et_2Zn in the presence of Pd(0) catalyst (Org. Lett., 2001, 3, 3627). Owing to its easy generation under the very mild reaction conditions, this methodology enable to synthesize various functionalized vinylic suifoxides stereoselectively(3) Synthesis of Amino Allenes by a Novel PalladiumCatalyzed Reaction. Amino allenes have attracted considerable interest in recent years, since they are versatile substrates for constructing various azacycles. We found a general and efficient synthesis of allenes including amino allenes using a palladium(0)/diethylzinc system: treatment of mesylates or trichloroacetates of 2 bromoalk 2 en 1 ols with diethylzinc and a palladium(0) catalyst affords various allenes bearing an aminoalkyl, alkyl, or aryl substituent in good to high yields (J. Org, Chem. 2002, 67, 1359)