The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2008

Herndon, James W.

doi:10.1016/j.ccr.2009.07.018

Cited by 45 publications

(1 citation statement)

References 1,117 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the seminal finding by Fischer and Maasböl some 40 years ago, thousands of heteroatom-stabilized carbene complexes L n MC(R)X (X = OR′, NR′ 2 , SR′, SnR′ 3 ) have been synthesized in view of their anticipated application scope in organic synthesis . Although the case of transition-metal α-P-substituted carbene complexes has been examined on several occasions, , the true phosphorus-containing homologues of Fischer carbenes, η 1 -α-phosphinocarbenes of the type L n MC(R)PR′ 2 , have remained extremely scarce and their reactivity has been virtually unexplored. − …”

Section: Introductionmentioning

confidence: 99%

Synthesis of η¹-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

et al. 2011

View full text Add to dashboard Cite

A series of η1-α-phosphinocarbene complexes of manganese, Cp(CO)2MnC(R)PR′R′′ (3; 3a: R = Ph, R′ = H, R′′ = Mes; 3b: R = Me, R′ = H, R′′ = Mes; 3c: R = Ph, R′ = R′′ = Ph; 3d: R = Ph, R′ = R′′ = N(i-Pr)2; 3e: R = Ph, R′ = Me, R′′ = Mes), was generated at low temperature upon nucleophilic addition of the primary phosphine H2PMes and secondary phosphines HPPh2, HP(N(i-Pr)2)2, or (±)-HPMeMes to the cationic carbyne complexes Cp(CO)2Mn+C−R ([1]+; [1a]+: R = Ph; [1b]+: R = Me), followed by deprotonation of the resulting α-phosphoniocarbene intermediates Cp(CO)2MnC(R)P+(H)R′R′′ ([2a−e]+). The η1-α-phosphinocarbene complexes 3c−e derived from secondary phosphines were found to be highly thermolabile, giving upon intramolecular CO insertion the η3-phosphinoketene complexes Cp(CO)Mn(η3-C(O)C(Ph)PR′R′′) (4c: R′ = R′′ = Ph, 4d: i-Pr2N; RR/SS-4e: R′ = Me, R′′ = Mes) in 80−95% yield. The η1-α-phosphinocarbene complexes 3a,b, bearing a mesityl substituent, were isolated in 57−65% yield. The availability of the phosphorus lone pair in such compounds was assessed by their reaction with borane, giving the corresponding adducts Cp(CO)2MnC(R)P(BH3)HMes (5a, R = Ph; 5b, R = Me). Complexes 3a,b slowly rearrange in a nonpolar solvent (benzene) to afford a mixture of the η3-phosphinoketene complexes Cp(CO)Mn(η3-C(O)C(R)PHMes) (4a, R = Ph; 4b, R = Me) and the η1-phosphaalkene complexes Cp(CO)2Mn(η1-P(Mes)C(H)R (6a, R = Ph; 6b, R = Me), and ultimately pure 6a,b as a mixture of E/Z stereoisomers (6a, E/Z 60:40; 6b, E/Z 55:45). By contrast, a stereoselective rearrangement of 3a,b into E-6a,b was observed in a polar solvent (THF), the process being considerably accelerated in the presence of catalytic amounts of base. Deprotonation of 3a by n-BuLi at −80 °C affords the dicarbonyl phosphidocarbene anion [Cp(CO)2MnC(Ph)PMes]Li ([7a]Li), which undergoes an instantaneous CO insertion process upon addition of traces of weak acids (H2O, t-BuOH) to give the cyclic monocarbonylacyl anion [Cp(CO)2 Mn(η2-C(O)C(Ph)PMes]Li ([8a]Li, R = Ph). Besides, deprotonation of 3a,b by t-BuOLi affords directly the cyclic monocarbonylacyl anions [8a,b]Li. The protonation of [8a]Li with various proton sources (HBF4·Et2O, NH4Claq, [Et3NH]Cl) leads to a stereoselective formation of E-6a, illustrating the key role of this anion in the stereoselective 3a → E-6a rearrangement. Alkylation of [8a]Li by MeI resulted in formation of η3-phosphinoketene complex RR/SS-4e as a single pair of diastereomers, whereas its treatment with iodine resulted in thermally unstable η3-phosphinoketene complex Cp(CO)Mn(η3-C(O)C(Ph)PIMes) (11), evolving at room temperature into the η1-phosphaalkene product Cp(CO)2Mn(η1-P(Mes)C(I)Ph) (12) of Z conformation. The solid-state structures of 3b, 4c, 4d, RR/SS-4e, and Z-12 are reported.

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis of η¹-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

et al. 2011

View full text Add to dashboard Cite

show abstract

[3+2] Cycloaddition of α,β‐Unsaturated Metal–Carbene Complexes

Takagi

Abe

2014

Methods and Applications of Cycloaddition Reactions in Organic Syntheses

View full text Add to dashboard Cite

Carbene‐Promoted Multicomponent Reactions

Monge

Iglesias‐Sigüenza

Mas‐Marzá

2015

Multicomponent Reactions

View full text Add to dashboard Cite

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2008

Cited by 45 publications

References 1,117 publications

Synthesis of η¹-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

Synthesis of η¹-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

[3+2] Cycloaddition of α,β‐Unsaturated Metal–Carbene Complexes

Carbene‐Promoted Multicomponent Reactions

Contact Info

Product

Resources

About

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2008

Cited by 45 publications

References 1,117 publications

Synthesis of η1-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

Synthesis of η1-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

[3+2] Cycloaddition of α,β‐Unsaturated Metal–Carbene Complexes

Carbene‐Promoted Multicomponent Reactions

Contact Info

Product

Resources

About

Synthesis of η¹-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations

Synthesis of η¹-α-Phosphinocarbene Complexes of Manganese and Mechanistic Insight into Their Base-Induced Transformations