conditions atom transfer products (17a–c, 18c,d) were obtained exclusively, whose regio- and stereochemistry were dependant on the olefinic acceptor. Thus, irradiation of the ester trans-16a or the phenyl derivative 16b (E/Z mixture) gives the trans-cyclopentyl derivatives 17a and 17b; the bromide 16c (R=Me) affords a mixture of the trans-cyclopentyl compound 17c and a comparable amount of the cyclohexyl
旁侧带有-(炔基)Co 2(CO)6单元的自由基以非常规的立体选择性和区域选择性在分子内添加至碳-碳双键。阳离子络合物13a(R = CO 2 Me)与Zn反应,仅生成反式-5- exo产物14a。由醇7a - d制得的不稳定的炔丙基
溴配合物16a - d用Et 3 B / O 2 / Ph 2 SiH 2或在辐射下进行环化。在后一种条件下,原子转移产物(17a– c,18c,d)仅获得,其区域
化学和立体
化学取决于烯烃受体。因此,该酯的照射反式- 16A或苯基衍
生物16B(É / Ž混合物),得到反式-环戊基衍
生物17A和17B ;
溴化物16c(R = Me)得到反式-环戊基化合物17c和相当量的环己基衍
生物18c的混合物;和母体
溴化物16d(R = H)仅转化为环己基衍
生物18d。庚烯衍
生物20d(R = H)仅环化至7-内环庚基衍
生物21d。有限的机械实验表明,自由基链的操作具有类似