Asymmetric Intramolecular C−H Insertions of Aryldiazoacetates
摘要:
[GRAPHICS]The enantioselectivity of Rh-2(SDOSP)(4) catalyzed C-H insertion of aryldiazoacetates is very dependent on the site of the C-H insertion. The highest enantioselectivity is obtained for insertion into methine C-H bonds.
[GRAPHICS]The enantioselective intramolecular C-H insertion reaction of aryldiazoacetates has been explored with use of dirhodium(II) carboxylate catalysts, which incorporate N-phthaloyl- or N-benzene-fused-phthaloyl-(S)-amino acids as chiral bridging ligands. Dirhodium tetrakis[N-phthaloyl-(S)tert-leucinate], Rh-2(S-PTTL)(4), has proven to be the catalyst of choice for this process, providing exclusively cis-2-aryl-3-methoxycarbonyl-2,3-dihydobenzofurans in up to 94% ee.
Enantioselective Synthesis of (−)-Maoecrystal V by Enantiodetermining C–H Functionalization
作者:Ping Lu、Artur Mailyan、Zhenhua Gu、David M. Guptill、Hengbin Wang、Huw M. L. Davies、Armen Zakarian
DOI:10.1021/ja510573v
日期:2014.12.24
evolution of a program directed at the enantioselective total synthesis of maoecrystal V, a highly modified ent-kauranoid, is described. An early stage chiral auxiliary-directed asymmetric C–H functionalization for the construction of a key benzofuran intermediate enabled the first asymmetric synthesis of the natural enantiomer of maoecrystal V, confirming the assigned stereochemistry. A divergent course
描述了针对 maoecrystal V(一种高度修饰的 ent-kauranoid)的对映选择性全合成的程序的演变。用于构建关键苯并呋喃中间体的早期手性辅助导向的不对称 C-H 官能化使 maoecrystal V 的天然对映异构体的首次不对称合成成为可能,证实了指定的立体化学。依赖于亲二烯体性质的中心分子内 Diels-Alder 反应的发散过程最初导致了 maoecrystal V 的一种意外且以前未知的异构体的发展,我们将其命名为 maoecrystal ZG。鉴于已报道的 maoecrystal V 的选择性和有效的细胞毒活性,还研究了 maoecrystal ZG 的细胞毒特性。
Asymmetric Intramolecular C−H Insertions of Aryldiazoacetates
作者:Huw M. L. Davies、Mônica V. A. Grazini、Emmanuel Aouad
DOI:10.1021/ol0157858
日期:2001.5.1
[GRAPHICS]The enantioselectivity of Rh-2(SDOSP)(4) catalyzed C-H insertion of aryldiazoacetates is very dependent on the site of the C-H insertion. The highest enantioselectivity is obtained for insertion into methine C-H bonds.