Highly enantioselective synthesis of bisoxindoles with two vicinal quaternary stereocenters via Lewis base mediated addition of oxindoles to isatin-derived ketimines

2014 ◽  
Vol 12 (32) ◽  
pp. 6085-6088 ◽  
Author(s):  
Zhongkai Tang ◽  
Yan Shi ◽  
Haibin Mao ◽  
Xuebin Zhu ◽  
Weipeng Li ◽  
...  
Keyword(s):  
Efficient Method ◽  
Enantioselective Synthesis ◽  
Lewis Base ◽  
Highly Efficient ◽  
Stereogenic Centers ◽  
Quaternary Stereocenters ◽  
Quaternary Stereogenic Centers

A highly efficient method provides access to the bisoxindole structure moiety with two vicinal quaternary stereogenic centers (>99 : 1 dr, >99% ee).

An Efficient Method for Constructing Cyclic β-Amino Acids Bearing Quaternary Stereocenters

Synlett ◽  
2019 ◽  
Vol 30 (05) ◽  
pp. 593-599 ◽  
Author(s):  
Shende Jiang ◽  
Guang Yang ◽  
Shuanglin Qin ◽  
Tongtong Liu ◽  
Yunhao Luo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Efficient Method ◽  
Ester Group ◽  
Chiral Auxiliary ◽  
Allyl Ester ◽  
Stereogenic Centers ◽  
Quaternary Stereocenters ◽  
High Yields ◽  
Quaternary Stereogenic Centers

This paper describes an efficient method for constructing cyclic β-amino acids bearing quaternary stereocenters. NaHMDS-promoted asymmetric α-alkylation was employed to obtain the key intermediates with quaternary stereogenic centers, which were subsequently reduced by NaBH4 in 10% methanol in THF, with high yields and high diastereoselectivities. By removing the allyl ester group and the chiral auxiliary, the corresponding cyclic β-amino acid hydrochlorides were finally obtained.

Phase-transfer catalyzed enantioselective α-alkylation of α-acyloxymalonates: construction of chiral α-hydroxy quaternary stereogenic centers

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77427-77430 ◽  
Author(s):  
Min Woo Ha ◽  
Sujee Choi ◽  
Seek Kim ◽  
Jun Young Lee ◽  
Jae Kyun Lee ◽  
...  
Keyword(s):  
Natural Products ◽  
Efficient Method ◽  
Phase Transfer ◽  
Enantioselective Synthesis ◽  
Tertiary Alcohols ◽  
Stereogenic Centers ◽  
Quaternary Stereogenic Centers

The enantioselective synthesis of α-acyloxy-α-alkylmalonates was developed as an efficient method for producing chiral α-tertiary alcohols, which are potentially valuable intermediates in the synthesis of natural products and pharmaceuticals.

scholarly journals NHC-Catalyzed Organocatalytic Asymmetric Approach to 2,2-Disubstituted Benzofuran-3(2H)-ones Containing Fully Substituted Quaternary Stereogenic Center

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 192 ◽  
Author(s):  
Zbigniew Rafiński
Keyword(s):  
Stetter Reaction ◽  
Highly Efficient ◽  
Stereogenic Centers ◽  
Michael Acceptors ◽  
High Yields ◽  
Stereogenic Center ◽  
Quaternary Stereogenic Centers ◽  
Triazolium Salts

A highly efficient and enantioselective approach to the synthesis of functionalized benzofuran-3(2H)-ones is presented. It proceeds via an intramolecular Stetter reaction using β,β-disubstituted Michael acceptors in the construction of five-membered rings with fully-substituted quaternary stereogenic centers and is promoted by terpene-derived triazolium salts. As a result, a series of chiral 2,2-disubstituted benzofuran-3(2H)-one derivatives with linear, branched, and cyclic aliphatic substitutions on the quaternary stereogenic center were obtained in high yields and with excellent enantioselectivities of up to 99% ee.

scholarly journals Enantioselective synthesis of gem-diarylalkanes by transition metal-catalyzed asymmetric arylations (TMCAAr)

2018 ◽  
Vol 9 (3) ◽  
pp. 546-559 ◽  
Author(s):  
Tao Jia ◽  
Peng Cao ◽  
Jian Liao
Keyword(s):  
Transition Metal ◽  
Enantioselective Synthesis ◽  
Transfer Reactions ◽  
Stereogenic Centers ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Quaternary Stereogenic Centers ◽  
Aryl Transfer

To date, enantiomerically enriched molecules containing gem(1,1)-diaryl containing tertiary or quaternary stereogenic centers have been readily accessed by transition metal-catalyzed enantioselective or stereoconvergent aryl transfer reactions.

Sign in / Sign up

Export Citation Format

Share Document