The first primary aminocatalytic direct cross-aldol reaction of acetaldehyde is presented. Among the various vicinal diamines screened, the L-tert-leucine derivative 1c in conjunction with (H4SiW12O40)0.25 was identified as the optimal catalyst; good catalytic activity (up to 99 % yield in 4 h), and high enantioselectivities (up to 92 % ee) were achieved for a range of donors, including aromatic aldehydes
Chiral Primary−Tertiary Diamine Catalysts Derived From Natural Amino Acids for <i>syn</i>-Aldol Reactions of Hydroxy Ketones
作者:Jiuyuan Li、Sanzhong Luo、Jin-Pei Cheng
DOI:10.1021/jo802557p
日期:2009.2.20
A series of primary-tertiary diamine catalysts were designed and synthesized from primary natural amino acids. Application of these new chiral catalysts in direct aldol reactions of α-hydroxyketones showed very good catalytic activity (up to 97% yield) and high syn selectivity (up to syn/ anti = 30:1, 99% ee).
从伯天然氨基酸设计合成了一系列伯叔二胺催化剂。这些新的手性催化剂在α-羟基酮的直接醛醇缩合反应中的应用显示出非常好的催化活性(高达97%的收率)和高的合成选择性(高达syn / anti = 30:1,99%ee)。
[EN] INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION<br/>[FR] INHIBITEURS DE LA RÉPLICATION DU VIRUS D'IMMUNODÉFICIENCE HUMAINE
申请人:VIIV HEALTHCARE (NO 5) LTD
公开号:WO2016172425A1
公开(公告)日:2016-10-27
Compounds of Formulas I-VI, including pharmaceutically acceptable salts thereof, and compositions and methods for treating human immunodeficiency virus (HIV) infection are set forth. Formula I is exemplified below: Formula (i)
Catalytic enantioselective α‐fluorination reactions of carbonyl compounds are among the most powerful and efficient synthetic methods for constructing optically active α‐fluorinated carbonyl compounds. Nevertheless, α‐fluorination of α‐nonbranched carboxylic acid derivatives is still a big challenge because of relatively high pKa values of their α‐hydrogen atoms and difficulty of subsequent synthetic
羰基化合物的催化对映选择性α-氟化反应是构建光学活性α-氟化羰基化合物的最有效,最有效的合成方法之一。然而,由于α-非支链羧酸衍生物的α-氢原子的p K a值相对较高,并且随后不进行差向异构化就很难进行合成转化,因此α-非支链羧酸衍生物的α-氟化仍然是一个很大的挑战。本文显示了3-(2-萘基)-1-丙氨酸衍生的酰胺的手性铜(II)络合物是N-(α-芳基乙酰基)和N的对映体和定点α-氟化的高效催化剂-(α-烷基乙酰基)3,5-二甲基吡唑。转化的底物范围非常广泛(25个实例,其中包括季铵化α-氟化α-氨基酸衍生物)。α-氟化产物几乎没有差向异构化地转化为相应的酯,仲酰胺,叔酰胺,酮和醇。
A New General Approach to Enantiomerically Pure Cyclic and Open-Chain (<i>R</i>)- and (<i>S</i>)-α,α-Disubstituted α-Amino Acids
racemic N-acylated α,α-disubstituted amino acids were resolved by coupling to chiral amines 15-18 derived from (S)-phenylalanine to form diastereoisomers 19/20 or 21/22 that could be separated by crystallization and/or flash chromatography on silica gel (Scheme 3). Selective cleavage via the 1,3-oxazol-5(4H)-ones 10a-p gave the corresponding optically pure α,α-disubstituted amino-acid derivatives 11 or