Samariumdiiodide mediated cyclizations of N‐acylatedindolederivatives bearing sulfinyl imine moieties afforded polycyclic tertiary carbinamines with moderate to excellent diastereoselectivities. Lithium bromide and water turned out to be the best additives to achieve these transformations in good yields. Using enantiopure sulfinyl imines the outcome strongly depends on the reactivity of the indole
New conditions for dearomatizingsamarium‐ketyl (hetero)arene cyclizations are reported. In many examples of these samariumdiiodide‐mediated reactions, lithium bromide and water can be used as additives instead of the carcinogenic and mutagenic hexamethylphosphoramide (HMPA). The best results were obtained for the cyclizations of N‐acylatedindolederivatives delivering the expected indolines in good
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.
US5880126A
申请人:——
公开号:US5880126A
公开(公告)日:1999-03-09
[EN] ASYMMETRIC SYNTHESIS OF ALLYL OR ALLENE OXINDOLES<br/>[FR] SYNTHÈSE ASYMÉTRIQUE D'OXINDOLES D'ALLYLE OU D'ALLÈNE
申请人:UNIV PENNSYLVANIA
公开号:WO2010008727A1
公开(公告)日:2010-01-21
The invention concerns processes for the preparation of a compound of the formula I comprising contacting a compound of formula II with a catalyst, said catalyst comprises (i) at least one of Pd and Cu and (ii) one or more of diamine, diphosphine and aminophosphine ligands; wherein Z is -C(R5)(R6)-C(R2)=C(R3)(R4) and Y is -C(R3)(R4)-C(R2)=C(R5)(R6) or Z is -C(R5)(R6)-C≡C-R3; Y is or -C(R3)=C=C(R5)(R6); X is NH, NR15, O or S; a is O or an integer from 1 to 4 and R1 -R7 and R15 are as defined in the specification.