Hiroaki Sasai 교수

Abstract This review focuses on a new concept in catalytic asymmetric reactions that was first realized for the use of heterobimetallic complexes. As these heterobimetallic complexes function as both a Brønsted base and as a Lewis acid, just like an enzyme, they make possible a variety of efficient catalytic asymmetric reactions. This heterobimetallic concept should prove to be applicable to a variety of new asymmetric catalyses. The first part of this review describes the development of rare‐ea

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBasic character of rare earth metal alkoxides. Utilization in catalytic carbon-carbon bond-forming reactions and catalytic asymmetric nitroaldol reactionsHiroaki Sasai, Takeyuki Suzuki, Shigeru Arai, Takayoshi Arai, and Masakatsu ShibasakiCite this: J. Am. Chem. Soc. 1992, 114, 11, 4418–4420Publication Date (Print):May 1, 1992Publication History Published online1 May 2002Published inissue 1 May 1992https://pubs.acs.org/doi/10.1021/ja00037a068https://do

Up to 94% ee can be achieved in the title reaction [Eq. (a)], which was previously only possible with enzymes. In this reaction LaLi3 tris(binaphthoxide) (LLB) imitates the function of enzymes by displaying both Lewis acidity and Brønsted basicity.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe First Heterobimetallic Multifunctional Asymmetric CatalystHiroaki Sasai, Takayoshi Arai, Yoshinori Satow, K. N. Houk, and Masakatsu ShibasakiCite this: J. Am. Chem. Soc. 1995, 117, 23, 6194–6198Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June 1995https://pubs.acs.org/doi/10.1021/ja00128a005https://doi.org/10.1021/ja00128a005research-articleACS PublicationsRequest reuse permissionsArticle Vi

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEfficient Diastereoselective and Enantioselective Nitroaldol Reactions from Prochiral Starting Materials: Utilization of La-Li-6,6'-Disubstituted BINOL Complexes as Asymmetric CatalystsHiroaki Sasai, Teruhisa Tokunaga, Shizue Watanabe, Takeyuki Suzuki, Noriie Itoh, and Masakatsu ShibasakiCite this: J. Org. Chem. 1995, 60, 23, 7388–7389Publication Date (Print):November 1, 1995Publication History Published online1 May 2002Published inissue 1 November 199

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic asymmetric nitroaldol reaction using optically active rare earth BINOL complexes: investigation of the catalyst structureHiroaki Sasai, Takeyuki Suzuki, Noriie Itoh, Koichi Tanaka, Tadamasa Date, Kimio Okamura, and Masakatsu ShibasakiCite this: J. Am. Chem. Soc. 1993, 115, 22, 10372–10373Publication Date (Print):November 1, 1993Publication History Published online1 May 2002Published inissue 1 November 1993https://pubs.acs.org/doi/10.1021/ja00

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic Asymmetric Synthesis of .alpha.-Amino Phosphonates Using Lanthanoid-Potassium-BINOL ComplexesHiroaki Sasai, Shigeru Arai, Yoshihiro Tahara, and Masakatsu ShibasakiCite this: J. Org. Chem. 1995, 60, 21, 6656–6657Publication Date (Print):October 1, 1995Publication History Published online1 May 2002Published inissue 1 October 1995https://pubs.acs.org/doi/10.1021/jo00126a003https://doi.org/10.1021/jo00126a003research-articleACS PublicationsReques

Teaming up: The title reaction has been developed to deliver the product α-alkylidene-γ-butyrolactones as single diastereomers with up to 98 % ee (see scheme; Ts=4-toluenesulfonyl). The enantioselective process is catalyzed by 1, which contains both Lewis base and Brønsted acid moieties.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic Asymmetric Michael Reactions Promoted by a Lithium-Free Lanthanum-BINOL ComplexHiroaki Sasai, Takayoshi Arai, and Masakatsu ShibasakiCite this: J. Am. Chem. Soc. 1994, 116, 4, 1571–1572Publication Date (Print):February 1, 1994Publication History Published online1 May 2002Published inissue 1 February 1994https://pubs.acs.org/doi/10.1021/ja00083a053https://doi.org/10.1021/ja00083a053research-articleACS PublicationsRequest reuse permissionsArtic

An enantio-, diastereo-, regio-, and chemoselective phosphine-catalyzed β,γ-umpolung domino reaction of allenic esters with dienones has been developed for the first time. The designed sequence, involving oxy-Michael and Rauhut-Currier reactions, produced highly functionalized tetrahydrobenzofuranones, bearing a chiral tetrasubstituted stereogenic center, in up to 96 % ee.

Facile, selective, and organic: Acid–base organocatalyzed aza-Morita–Baylis–Hillman/aza-Michael domino reactions of α,β-unsaturated carbonyl compounds 1 with N-tosylimines 2 have been developed. The enantioselective process produces the highly functionalized isoindoline as a single diastereomer (Ts=4-toluenesulfonyl).

This review describes our recent efforts in the development of chiral dinuclear vanadium complexes that work as dual activation catalysts for the oxidative coupling of 2-naphthols. The dinuclear vanadium(iv) complex (R(a),S,S)- was prepared by complexation of VOSO(4) with the Schiff base derived from (R)-3,3'-diformyl-2,2'-dihydroxy-1,1'-binaphthyl () and (S)-tert-leucine. Since the dinuclear vanadium(iv) complex was found to be readily oxidized to afford a corresponding vanadium(v) species duri