Detail of "31126-95-1"

Reference

Ligand effects in the Rh(II) catalyzed reaction of a-diazo ketoamides

Ligand effects in the Rh(II) catalyzed reaction of a-diazo ketoamides. Mejia-Oneto, Jose M.; Padwa, Albert (Department of Chemistry, Emory University, Atlanta, GA 30322, USA). Tetrahedron Letters, 45(49), 9115-9118 (English) 2004 Elsevier B.V. CODEN: TELEAY. ISSN: 0040-4039. DOCUMENT TYPE: Journal CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) Dirhodium tetracarboxylate or tetracarboxamide complexes act as catalysts for reactions of a-diazoesters contg. amides and pendant alkenes or heterocycles such as I to give either polycycles such as II or methanoazepinediones such as III depending on the ligands present in the rhodium catalysts. In the presence of dirhodium tetrapivaloate, I undergoes intramol. cyclocondensation followed by [3+2] cycloaddn. through a carbonyl ylide intermediate to give II as the sole product in 98% yield. In the presence of dirhodium tetrakis(heptafluorobutanoate), reaction of I yields both II in 62% yield and III (likely derived from via C-H insertion of I followed by dealkoxycarboxylation of the intermediate) in 32% yield. Other dirhodium compds. catalyze the intramol. 821306-53-0 and 31126-95-1 are also in the experiment. cycloaddn. of I to provide II and III with varying levels of chemoselectivity. In the presence of dirhodium tetrapivaloate, the thiophene contg. substrate IV undergoes carbonyl ylide formation and intramol. cycloaddn. to give the polycycle V in 35% yield, indicating that tethered thiophenes can also undergo tandem cyclization-cycloaddn. reactions. .