Rhodium Catalyzed 1,4-Conjugate Addition of 1,5-Azastibocines with Electron Deficient Olefins

Kakusawa, Naoki; Kurita, Jyoji

doi:10.1248/cpb.56.1502

Cited by 11 publications

(8 citation statements)

References 26 publications

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“…From these results, it was concluded that 1,5-azastibocines 428 were good aryl donors in the 1,4-conjugate addition (Scheme 204). 353 The proposed catalytic cycle for the conjugate addition is similar to the mechanism for the 1,4-addition of organoboronic acid to enones (Scheme 205). 60 1,5-azastibocine was transmetallated to a suitable Rh catalyst to provide aryl-rhodium complex 430.…”

Section: Miscellaneousmentioning

confidence: 91%

“…350 It is noteworthy that alkyl zirconocene chloride is an ineffective reagent under the present reaction conditions, and the same was noticed in Rh(I)-catalyzed reactions with imines. [352][353][354][355] Since the transfer of the alkyl group from Zr to Rh is slower than the alkenyl group, 356 this 1,4-addition reaction of 1 is expected to involve the creation of alkenyl rhodium species via the transmetallation at the first stage. The overall process is illustrated in Scheme 195, in which the 1,4-adducts are obtained from a catalytic cycle as a Zr-enolate 403.…”

Section: Organozirconiumsmentioning

confidence: 99%

“…However, a substituent on the double bond decreased the yield of the 1,4-addition (Scheme 203). 353 Under the optimal conditions, different Sb-aryl-1,5-azastibocines 428a-d were reacted with methyl vinyl ketone 335g (Scheme 204). Irrespective of the electronic nature of the substituent on the aryl group, all of the 1,4-conjugate addition could be performed at 100°C to obtain the products in satisfactory yields.…”

Section: Miscellaneousmentioning

confidence: 99%

See 2 more Smart Citations

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Heravi

Dehghani

Zadsirjan

2016

Tetrahedron: Asymmetry

109

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Rh-catalyzed asymmetric 1,4-addition reactions to a,b-unsaturated carbonyl and related compounds: an update Available online xxxx Dedicated to my son, OMID on the occasion of his 35th birthday. a b s t r a c tThe Rh-catalyzed asymmetric 1,4-addition of organometallic reagents to an appropriate receptor has been a growing area of research over the last decade. The receptors for such a 1,4-addition reaction are chiefly a,b-unsaturated ketones, esters, amides, enones, nitroalkenes, and occasionally phosphonates etc. This reaction in the presence of chiral rhodium complexes introduce the aryl and alkenyl groups at the b-position of the above electron poor olefins, enantioselectively. Chiral Rh complexes similar to other transition metals can be added to some electron poor olefins, in turn making them viable to attack by various organometallic reagents for highly enantioselective C-C bond formation. The Rh-catalyzed asymmetric 1,4-addition of organometallic reagents to electron poor olefins has been reviewed in 2003. Due to the importance of the asymmetric C-C bond formation via 1,4-conjugate addition reactions and the number of such reactions catalyzed by Rh-complexes, in this review we highlight the recent advances in Rh-complex asymmetric catalyzed 1,4-addition reactions since 2003.

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Section: Miscellaneousmentioning

confidence: 91%

Section: Organozirconiumsmentioning

confidence: 99%

Section: Miscellaneousmentioning

confidence: 99%

See 1 more Smart Citation

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Heravi

Dehghani

Zadsirjan

2016

Tetrahedron: Asymmetry

109

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“…26,27) We also reported that Sb(V) compounds work as useful pseudo-halides in Pd-catalyzed cross-coupling reactions.…”

mentioning

confidence: 98%

“…14,[23][24][25] In the course of our studies on organoantimony (Sb) compounds as synthetic reagents, we have recently demonstrated that Sb(III) compounds were efficient transmetallating agents for transition metal-catalyzed cross-coupling reactions. 26,27) We also reported that Sb(V) compounds work as useful pseudo-halides in Pd-catalyzed cross-coupling reactions. 28) These results stimulated us to employ them in Cu-mediated arylation of amines.…”

mentioning

confidence: 98%

Pentavalent Organoantimony Compounds as Mild N-Arylating Agents for Amines: Cu-Mediated Ullmann-Type N-Arylation with Tetraarylantimony(V) Acetates

Qin

Kakusawa

et al. 2009

CHEMICAL & PHARMACEUTICAL BULLETIN

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Simple and mild Cu-mediated arylation of various amines by use of tetraarylantimony acetate (Ar 4 SbOAc) is described. The Ullmann-type condensation of Ar 4 SbOAc with aliphatic and electron rich aromatic amines proceeded efficiently in the presence of copper(II) acetate. The arylation can be carried out under aerobic conditions without care of exogenous oxygen. This simple procedure exceeds the conventional Ullmann condensation which often requires harsh reaction conditions. Key words tetraarylantimony(V) acetate; N-arylation; Ullmann condensation; copper(II) acetate; aerobic reactionThe aryl-nitrogen bond can be found in a wide range of biologically active compounds such as bradykinin (BK) receptor antagonist martinellic acid 1) and opioid receptor agonist CJ-15161.2) Thus, it is desirable to develop simple and efficient methods for aryl-nitrogen bond formation. Among them, research on transition metal-catalyzed C-N bond formation has flourished recently. For example, remarkable progress in bulky and electron rich phosphine ligands has enabled Pd-and Ni-catalyzed cross-couplings of amines and alcohols with aryl halides and sulfonates.3,4) These transition metal-catalyzed reactions have been recognized as one of the most reliable methods for C-N bond formation.5-8) Direct C-H functionalization to form C-N bonds has also been another convenient entry for C-N cross-coupling using transition metal catalysts.9,10) However, these elaborated catalysts and phosphine ligands often tend to be sensitive to air oxidation and hydrolysis by moisture. These problems make the traditional Ullmann condensation attractive in large and industrial scale applications employing low price, non-toxic, and air-stable Cu reagents. [11][12][13][14] Because traditional Cu-mediated Ullmann condensation has been conducted and limited by harsh reaction conditions, 15) many improvements in Ullmann-type C-N bond formation have recently been made. For example, aryl halides employed as aryl donors in the traditional Ullmann condensation were replaced with highly reactive transmetallating agents such as organo-boron, 13,14,[16][17][18][19] -silicon, 20) -stannane, 19,21) -lead, 14,22) and -bismuth compounds.14, [23][24][25] In the course of our studies on organoantimony (Sb) compounds as synthetic reagents, we have recently demonstrated that Sb(III) compounds were efficient transmetallating agents for transition metal-catalyzed cross-coupling reactions. 26,27) We also reported that Sb(V) compounds work as useful pseudo-halides in Pd-catalyzed cross-coupling reactions. 28)These results stimulated us to employ them in Cu-mediated arylation of amines.As for Sb-mediated N-and O-arylation of amines and alcohols, triphenylantimony ortho-phenylenedioxides and triphenylstibane have been reported to function as aryl donors. 29,30) However, the reactions are not so efficient, in that they must be carried out using amines or alcohols as solvents at high temperature. Thus, we focused on highly reactive Sb(V) compounds as Cu-mediated N-arylating agents. 31,32...

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Alternatives to Organoboron Reagents in Rhodium‐Catalyzed Conjugate Additions

Hargrave

Allen

Frost

2010

Chemistry An Asian Journal

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The rhodium-catalyzed conjugate addition of organoboron reagents to alkene acceptors has emerged as an important methodology in organic synthesis. The process results in the formation of new carbon-carbon bonds, and in principle, can create new stereocenters at both the alpha and beta carbon atoms of the acceptor. Other organometallics are known to participate in the key transmetalation to rhodium and are becoming more established in stereoselective synthesis (notably arylzinc reagents). This Focus Review will describe recent developments in the use of alternative organometallic donors to organoboron reagents in rhodium-catalyzed conjugate addition reactions and their growing applications in synthesis.

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Rhodium Catalyzed 1,4-Conjugate Addition of 1,5-Azastibocines with Electron Deficient Olefins

Cited by 11 publications

References 26 publications

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Pentavalent Organoantimony Compounds as Mild N-Arylating Agents for Amines: Cu-Mediated Ullmann-Type N-Arylation with Tetraarylantimony(V) Acetates

Alternatives to Organoboron Reagents in Rhodium‐Catalyzed Conjugate Additions

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