Copper(II)- and Palladium(II)-Catalyzed Enantioselective Claisen Rearrangement of Allyloxy- and Propargyloxy-Indoles to Quaternary Oxindoles and Spirocyclic Lactones
作者:Trung Cao、Elizabeth C. Linton、Joshua Deitch、Simon Berritt、Marisa C. Kozlowski
DOI:10.1021/jo302039n
日期:2012.12.21
In this Article, a strategy to obtain highly enantio-selective catalysts for the Claisen rearrangement of allyloxy- and propargyloxy-indoles is outlined. Ultimately, copper BOX and palladium BINAP or PHOX catalysts were discovered as superior in catalyzing Claisen rearrangements of allyloxy- or proparyloxy-substituted indoles to generate oxindoles bearing allyl- or allenyl-substituted quaternary centers. This method proved to be tolerant of a broad range of functional groups. Tandem reactions of the silyl-allene products provide rapid access to a variety of spirocyclic oxindoles in one operation.
Asymmetric Synthesis of Allenyl Oxindoles and Spirooxindoles by a Catalytic Enantioselective Saucy-Marbet Claisen Rearrangement
作者:Trung Cao、Joshua Deitch、Elizabeth C. Linton、Marisa C. Kozlowski
DOI:10.1002/anie.201107417
日期:2012.3.5
Saucy selection: The first catalytic, enantioselectiveSaucy–MarbetClaisenrearrangement has been achieved. Palladium(II) (R)‐binap or tBuphox catalysts L*Pd(SbF6)2 were employed to generate allenyloxindoles or spirolactones bearing a quaternary center with up to 98 % ee.