Rhodium-Catalyzed Enantioselective Intramolecular [4+2] Cycloaddition using a Chiral Phosphine-Phosphite Ligand: Importance of Microwave-Assisted Catalyst Conditioning
The use of modular α,α,α′,α′-tetraaryl-1,3-dioxolane-4,5-dimethanol (TADDOL)- and 1,1′-bi-2-naphthol (BINOL)-derived phosphine-phosphite ligands (L2*) in the asymmetric rhodium-catalyzed intramolecular [4+2] cycloaddition (“neutral” Diels–Alder reaction) of (E,E)-1,6,8-decatriene derivatives (including a 4-oxa and a 4-aza analogue) was investigated. Initial screening of a small ligandlibrary led to the
Rhodium-Catalyzed [5+2] Cycloaddition
Reactions in Water
作者:Paul Wender、Jennifer Love、Travis Williams
DOI:10.1055/s-2003-40357
日期:——
water-soluble rhodium catalyst is reported along with its ability to effect [5+2] cycloaddition reactions in water. This water-soluble catalyst is recyclable, is readily separated from the or ganic product, and allows one to avoid or minimize the use of or ganic solvents, the major waste stream of most organic reactions.
On the asymmetric rh(I) catalyzed [4+2] cycloisomerization reaction. Electronic and torsional ligand control of absolute stereoselection.
作者:Lydia McKinstry、Tom Livinghouse
DOI:10.1016/s0040-4020(01)80636-0
日期:1994.1
The use of bisphosphine ligands related to DIOP as chiral modifiers in the Rh(I) catalyzed [4+2] cycloisomerization reaction results in moderate to good levels of enantioselection. The mode of absolute stereoinduction is subject to electronic and torsional modification of the chelating ligand.
A rhodium catalyst is reported that catalyzes the cycloisomerization of dieneynes and trienes. This cycloisomerization reaction, formally the equivalent of an unactivated Diels-Alder reaction, proceeds at room temperature with [Rh(DIPHOS)(CH2Cl2)(2)] SbF6 as the catalyst. (C) 1998 Elsevier Science Ltd. All rights reserved.