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Multicomponent Queuing Cascades of Bicyclopropylidene, Carbon Monoxide and Aryl Iodides or Aryl Thiols
Author(s) -
von Seebach Malte,
Grigg Ronald,
de Meijere Armin
Publication year - 2002
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200210)2002:19<3268::aid-ejoc3268>3.0.co;2-h
Subject(s) - chemistry , aryl , carbon monoxide , intramolecular force , steric effects , nucleophile , yield (engineering) , medicinal chemistry , palladium , monoxide , stereochemistry , organic chemistry , catalysis , alkyl , materials science , metallurgy
Bicyclopropylidene ( 1 ) reacts with N ‐(2‐iodophenyl)‐4‐methylbenzenesulfonamide ( 2 ‐NTs) and carbon monoxide (2−3 bar) under mild conditions in a novel palladium‐catalysed tetramolecular cascade to give the dispiro compound 3 ‐NTs (61%). The structure of 3 ‐NTs was determined by X‐ray analysis. With ortho ‐iodophenol ( 2 ‐OH) replacing 2 ‐NTs a mixture of 3 ‐O (20%) and 3,4‐dihydro‐2 H ,5 H ‐pyrano[3,2‐c]chromen‐2‐one ( 4 ‐O; 11%) was obtained. Mechanistically this cascade is interpreted in terms of the acylation of 1 followed by a cyclopropylcarbinyl‐homoallyl rearrangement, carbon monoxide insertion and intramolecular trapping of a nucleophile. Various thiophenols reacted with 1 and CO (2−3 bar) to give the thiocarbonylated products 14a − d,g and 15a − c,g (33−77% yield). With ortho ‐ or para ‐halo‐substituted thiophenols as substrates the vinyl lactones 16e − h (31−55% yield) were obtained in a novel palladium‐catalysed five‐component cascade. The outcome of this cascade is discussed in terms of the electronic and steric properties of the thiophenols. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)