Enantiocontrolled Macrocycle Formation by Catalytic Intramolecular Cyclopropanation
作者:Michael P. Doyle、Wenhao Hu、Brant Chapman、Alan B. Marnett、Chad S. Peterson、Justin P. Vitale、Sarah A. Stanley
DOI:10.1021/ja9945414
日期:2000.6.1
Stereoselectivity in intramolecular cyclopropanation reactions resulting in cyclopropane fusion with ten- and larger-membered rings has been examined using chiral copper(I) and dirhodium(II) catalysts. The influence of alkene structure and catalyst has been obtained using the 1,2-benzenedimethanol linker between the allylic double bond and diazoacetate. Control features in the addition reaction, especially
使用手性铜 (I) 和铷 (II) 催化剂研究了分子内环丙烷化反应中的立体选择性,导致环丙烷与十元和更大元环融合。使用烯丙基双键和重氮乙酸酯之间的 1,2-苯二甲醇连接体已经获得了烯烃结构和催化剂的影响。加成反应中的控制特征,特别是非对映选择性和对映选择性,已经阐明,它们与金属本身或其伴随的配体有关,这些配体影响烯烃到卡宾中心的轨迹。已使用选定的铜 (I) 和二铑 (II) 催化剂确定了环大小(从五元环到二十元环)对立体选择性的影响,作为环大小函数的立体控制的变化可以理解为由于烯烃轨迹到卡宾中心的变化。当 dirhodium 催化时,从苄基位置提取氢化物会伴随加成...
Macrocycle Formation by Catalytic Intramolecular Cyclopropanation. A New General Methodology for the Synthesis of Macrolides
作者:Michael P. Doyle、Chad S. Peterson、Marina N. Protopopova、Alan B. Marnett、Dann L. Parker,、Doina G. Ene、Vincent Lynch
DOI:10.1021/ja971687z
日期:1997.9.1
Catalytic intramolecular cyclopropanation by diazoacetates onto a remote carbon−carbon double bond resulting in the formation of 9- to 20-membered ring lactones is reported. When competition exists between proximal allylic and remote olefinic cyclopropanation, macrocyclization is favored by catalysts of increasing electrophilicity: Rh2(pfb)4 > Rh2(OAc)4, Cu(MeCN)4PF6 > Rh(cap)4, and Cu(acac)2. Terpene