The Use of Bis(trimethylsilyl)acetamide and Bis (trimethylsilyl)urea for Protection and as Control Reagents in Synthesis

Gihani, M. T. El; Heaney, H.

doi:10.1055/s-1998-2043

Cited by 43 publications

(20 citation statements)

References 96 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The preligand 15 was tested in the Pd‐catalyzed enantioselective alkylation of unsymmetrical diketones in the presence of bis(trimethylsilyl)acetamide (BSA) 29. 30 Surprisingly, the best results were obtained with an excess of four equivalents of BSA.…”

Section: Methodsmentioning

confidence: 99%

Enantioselective Catalysis with Chiral Phosphine Oxide Preligands

2004

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

Enantioselective Catalysis with Chiral Phosphine Oxide Preligands

2004

View full text Add to dashboard Cite

show abstract

“…No reaction occurred when a variety of bases, such as NaH, lithium diisopropylamide, 1,1,3,3-tetramethyguanidine, or diisopropylethylamine, were used. In contrast to other bases, N,O-bis(trimethysilyl)-acetamide (BSA) 29) promoted the reaction very efficiently to afford the corresponding product (S)-8 in 94% yield and in 99% ee (Chart 9).…”

Section: Chart 7 Stereoselective Synthesis Of Chiral Diaminophosphinmentioning

confidence: 99%

Development of New Methods in Organic Synthesis and Their Applications to the Synthesis of Biologically Interesting Natural Products

Hamada

2012

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

2,6-Dimethyl-9-Aryl-9-phosphabicyclo[3.3.1]nonanes (9-PBN and 9-NapBN) and the chiral diaminophosphine oxides (DIAPHOXs) derived from aspartic acid have been introduced as useful ligands and preligands, respectively, for transition metal-catalyzed asymmetric synthesis. anti-Selective asymmetric hydrogenation of α-amino-β-ketoesters using Ru-, Rh-, Ir-, and Ni-catalysts through dynamic kinetic resolution have been developed for the first time, producing efficiently important anti β-hydroxy-α-amino acids. The total synthesis of several biologically active natural products was achieved by use of the transition metal-catalyzed reaction using DIAPHOX, anti-selective asymmetric hydrogenation, and reactions developed by us. Synthesis of tangutorine, an antitumor indole alkaloid, has been enantioselectively achieved for the first time. Enantioselective synthesis of a martinelline chiral core was accomplished using the asymmetric tandem Michael-Aldol reaction as a key step developed by us. This synthesis represents the formal total synthesis of martinelline and martinellic acid. Papuamide B was synthesized through the elucidation of unknown stereostructures by using the anti-selective asymmetric hydrogenation and reactions developed by us.

show abstract

“…No reaction occurred when a variety of bases such as NaH, lithium diisopropylamide, 1,1,3,3‐tetramethylguanidine and diisopropylethylamine was used. In contrast to other bases, N,O ‐bis(trimethylsilyl)acetamide (BSA)16 promoted the reaction very efficiently to afford the corresponding product 8 in 94% yield and 99% ee (Scheme ).…”

Section: Pd‐catalyzed Asymmetric Allylic Alkylation Using (Srp)‐diapmentioning

confidence: 99%

“…In the case of reaction type B, kinetic experiments also indicate that the rate‐determining nucleophilic attack of the enol silyl ether, derived from 14a and BSA,16 to a cationic π‐allylpalladium complex is achieved in cooperation with a single molecule of Zn(OAc) 2 . This fact led us to hypothesize that a nitrogen atom on the sidearm in 12 could fix the prochiral nucleophile in the appropriate position through a secondary ligand substrate interaction22 mediated by Zn metal.…”

Section: Source Of Enantioselection In the Construction Of Quaternarymentioning

confidence: 99%

Pd‐catalyzed asymmetric allylic substitution reactions using P‐chirogenic diaminophosphine oxides: DIAPHOXs

Nemoto

Hamada

2007

The Chemical Record

View full text Add to dashboard Cite

This paper describes the development of a new class of chiral phosphorus ligand: aspartic acid-derived P-chirogenic diaminophosphine oxides, DIAPHOXs, and their application to several Pd-catalyzed asymmetric allylic substitution reactions. Pd-catalyzed asymmetric allylic alkylation was initially examined in detail using diaminophosphine oxides 1a, resulting in the highly enantioselective construction of quaternary stereocenters. Mechanistic investigations revealed that 1a is activated by N,O-bis(trimethylsilyl)acetamide-induced tautomerization to afford a trivalent diamidophosphite species 12, which functions as the actual ligand. Furthermore, asymmetric allylic amination was examined using Pd-DIAPHOX catalyst systems, providing a variety of chiral allylic amines.

show abstract

The Use of Bis(trimethylsilyl)acetamide and Bis (trimethylsilyl)urea for Protection and as Control Reagents in Synthesis

Cited by 43 publications

References 96 publications

Enantioselective Catalysis with Chiral Phosphine Oxide Preligands

Enantioselective Catalysis with Chiral Phosphine Oxide Preligands

Development of New Methods in Organic Synthesis and Their Applications to the Synthesis of Biologically Interesting Natural Products

Pd‐catalyzed asymmetric allylic substitution reactions using P‐chirogenic diaminophosphine oxides: DIAPHOXs

Contact Info

Product

Resources

About