基于 BINOL 的硼酸酯和硼翁盐的合成、结构和催化活性。

Synthesis, structures and catalytic activity of some BINOL based boronates and boronium salts.

机构信息

Department of Chemistry and Biochemistry, Texas Tech University, Memorial Dr. & Boston, Lubbock, TX 79409, USA.

出版信息

Dalton Trans. 2021 Apr 14;50(14):5044-5049. doi: 10.1039/d1dt00842k. Epub 2021 Mar 29.

Abstract

The BINOL supported chiral boronate ester [CHOBCF(THF)] [(R)-1], [CHOBCF(O[double bond, length as m-dash]PEt)] [(R)-3] and [CHOBCF] [(R,R)-2] as well as the chiral boronium salts [CHOB(O[double bond, length as m-dash]PEt)][B(OCH)], [(R)-6] and [CHOB(O[double bond, length as m-dash]SMe)][B(OCH)] [(R)-7] have been synthesized, characterized by NMR spectroscopy, and the solid state structures of [(R)-1], [(R,R)-2] and [(R)-3] determined. Chiral ester [(R)-1] was found to be a potent Lewis acid, similar to B(CF), and capable of rapidly catalyzing the annulation of (R)-, (S)- and rac-styrene oxide with nitrone PhCH[double bond, length as m-dash]N(O)Me to trans-2-methyl-3,6-diphenyl-1,4,2-dioxazine (trans-11) with high regio- and diastereoslectivities.

摘要

BINOL 支持的手性硼酸酯 [CHOBCF(THF)] [(R)-1]、[CHOBCF(O[双 bond, length as m-dash]PEt)] [(R)-3] 和 [CHOBCF] [(R,R)-2] 以及手性硼盐 [CHOB(O[双 bond, length as m-dash]PEt)][B(OCH)]、[(R)-6] 和 [CHOB(O[双 bond, length as m-dash]SMe)][B(OCH)] [(R)-7] 已被合成，通过 NMR 光谱进行了表征，并确定了 [(R)-1]、[(R,R)-2] 和 [(R)-3] 的固态结构。发现手性酯 [(R)-1] 是一种有效的路易斯酸，类似于 B(CF)，能够快速催化 (R)-、(S)-和 rac-氧化苯乙烯与亚硝酮 PhCH[双 bond, length as m-dash]N(O)Me 的环加成反应，以高区域和立体选择性生成反式-2-甲基-3,6-二苯基-1,4,2-二恶嗪 (trans-11)。