Iridium Complex-Catalyzed Highly Selective Organic Synthesis Iridium Complex-Catalyzed Highly Selective Organic Synthesis
نویسنده
چکیده
Synlett 2002, No. 12, Print: 02 12 2002. Art Id.1437-2096,E;2002,0,12,1954,1965,ftx,en;A30202ST.pdf. © Georg Thieme Verlag Stuttgart · New York ISSN 0936-5214 Abstract: Two different synthetic reactions catalyzed by an iridium complex are discussed. The first is allylic alkylation and allylic amination. This reaction proceeds via a -allyl iridium intermediate. The selectivity strongly depends on the structure of the allylic esters. Highly branched product-selective allylic substitution and highly Z-selective allylic substitution were achieved. The selectivities of allylic substitution described here have not been achieved in previous studies with other transition metal complexes. The second reaction is [2+2+2] cycloaddition of , -diynes with monoynes. This reaction proceeds via iridacyclopentadiene and tolerates various functional groups. Functionalized monoynes can be used. These results show that an iridium complex can be a useful catalyst for carbon-carbon and carbon-heteroatom bond formation.
منابع مشابه
Enantioselective construction of C-chiral allylic sulfilimines via the iridium-catalyzed allylic amination with S,S-diphenylsulfilimine: asymmetric synthesis of primary allylic amines.
We have devised a highly regio- and enantioselective iridium-catalyzed allylic amination reaction with the sulfur-stabilized aza-ylide, S,S-diphenylsulfilimine. This process provides a robust and scalable method for the construction of aryl-, alkyl- and alkenyl-substituted C-chiral allylic sulfilimines, which are important functional groups for organic synthesis. Additionally, the combination o...
متن کاملEnantioselective synthesis of anti homoallylic alcohols from terminal alkynes and aldehydes based on concomitant use of a cationic iridium complex and a chiral phosphoric acid.
We report a highly diastereo- and enantioselective synthesis of anti homoallylic alcohols from terminal alkynes via (E)-1-alkenylboronates based upon two catalytic reactions: a cationic iridium complex-catalyzed olefin transposition of (E)-1-alkenylboronates and a chiral phosphoric acid-catalyzed allylation reaction of aldehydes.
متن کاملSynthesis of benzimidazoles via iridium-catalyzed acceptorless dehydrogenative coupling.
Iridium-catalyzed acceptorless dehydrogenative coupling of tertiary amines and arylamines has been developed. A number of benzimidazoles were prepared in good yields. An iridium-mediated C-H activation mechanism is suggested. This finding represents a novel strategy for the synthesis of benzimidazoles.
متن کاملMultidirectional Synthesis of Substituted Indazoles via Iridium-Catalyzed C-H Borylation.
In the absence of a steric directing group, iridium-catalyzed C-H borylation of N-protected indazoles occurs rapidly and selectively at C-3 and the resulting boronate esters can be utilized in a range of downstream conversions. The functional group tolerance of the iridium-catalyzed C-H borylation reaction enables simple and efficient multidirectional syntheses of substituted indazoles to be re...
متن کاملNickel-Catalyzed Double Bond Transposition of Alkenyl Boronates for in Situ syn-Selective Allylboration Reactions.
The transposition of a homoallyl pinacol boronic ester was realized by a highly reactive nickel-catalyst system comprising NiCl2(dppp), zinc powder, ZnI2, and Ph2PH. The in situ generated Z-crotyl pinacol boronic esters were reacted with various aldehydes to form syn-homoallylic alcohols in high diastereoselectivities. The present nickel-catalyzed reaction is complementary to the iridium-cataly...
متن کامل