Highly stereoselective kinetic resolution of α-allenic alcohols: an enzymatic approach
作者:Wenhua Li、Zuming Lin、Long Chen、Xuechao Tian、Yan Wang、Sha-Hua Huang、Ran Hong
DOI:10.1016/j.tetlet.2015.12.098
日期:2016.2
A highly efficient lipase AK-catalyzed direct kinetic resolution of a variety of α-allenic alcohols was developed. With the complementary to previous studies, the current reaction system is effective on a broad range of substituents (R1) at C(1), such as alkyl, aryl, alkenyl, and alkynyl groups. The Jones–Burgess empirical model was modified to interpret the reversed selectivity during the acetylation
Peptide nucleic acid (PNA) is a nucleic acid mimic in which the deoxyribose–phosphate was replaced by a peptide-like backbone. The absence of negative charge in the PNA backbone leads to several unique behaviors including a stronger binding and salt independency of the PNA–DNA duplex stability. However, PNA possesses poor aqueous solubility and cannot directly penetrate cell membranes. These are major
The present invention relates to a compound of the formula ##STR1## wherein X.sup.1, R.sup.1, R.sup.2, OP, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and R.sup.0 are as described herein, and their pharmaceutically acceptable salts thereof carrying an acidic and/or basic substituent. The compound of formula I as well as their pharmaceutically acceptable salts inhibit DNA gyrase activity in bacteria and possess antibiotic, especially antibacterial activity against microorganisms and can be used in the control or prevention of infectious diseases.
Mannich-type reactions of aldehydes with secondary amines and a ketene silyl acetal were promoted by trimethoxyborane in DMSO to afford the corresponding β-amino esters in good yields. B(OMe)3 also promoted Ugi-typereactions ofaldehydes with secondary amines and isocyanides in 1,2-dichloroethane, which leads to the formation of α-amino amides. In these reactions, trimethoxyborane serves as an inexpensive
Diarylborinic Acid Derivatives as a Catalytic Iminium Ion Generator in the Mannich-Type Reaction Using Secondary Amines, Aldehydes, and Ketene Silyl Acetals
作者:Michinori Suginome、Yusuke Tanaka、Tomoaki Hasui
DOI:10.1055/s-2008-1072724
日期:2008.5
Reactions of secondary amines, aldehydes, and ketene silyl acetals were efficiently promoted by catalytic amounts of diarylborinic acid esters, Ar 2 B(OR), affording β-amino esters selectively with no formation of the corresponding β-hydroxy esters.
催化量的二芳基硼酸酯 Ar 2 B(OR) 有效地促进了仲胺、醛和乙烯酮甲硅烷基缩醛的反应,选择性地提供了 β-氨基酯,而不会形成相应的 β-羟基酯。