Asymmetric Grignard Synthesis of Tertiary Alcohols through Rational Ligand Design
作者:Bartosz Bieszczad、Declan G. Gilheany
DOI:10.1002/anie.201610462
日期:2017.4.3
enantioselective construction of tertiaryalcoholsthrough the direct addition of organomagnesium reagents to ketones. Discovered by rational ligand design based on a mechanistic hypothesis, it has an unprecedented broad scope. It utilizes a new type of chiral tridentate diamine/phenol ligand that is easily removed from the reaction mixture. It is exemplified by application to a formal asymmetric synthesis
Enantioselective Additions of Aryltitanium Tris(isopropoxide) to Ketones: Structure of [(<i>i-</i>PrO)<sub>2</sub>Ti{μ-(<i>S</i>)-BINOLate}(μ-O-<i>i-</i>Pr)TiPh(O-<i>i-</i>Pr)<sub>2</sub>], Study of Mechanistic and Stereochemical Insights
possesses a pocket structure and has been illustrated as the key active species for addition reactions of both aldehydes and ketones. Mechanistic and stereochemical insights concerning addition reactions of organometallicreagents to organic carbonyls are rationalized based on the pocket structure and pocket size of (S)‐4.
ARTI的芳基的加成反应(O-异PR)3至芳族的,杂芳族,或α,β不饱和酮中描述,产生良好的叔醇来达到97%的对映选择性优良EE。二钛配合物[[ i- PrO)2 Ti μ-(S)-BINOLate}(μ-O- i - Pr)TiPh(O- i- Pr)2 ] [(S)-4 ]的结构同时具有手性导向配体,并据报道有亲核试剂。复数(S)‐ 4具有口袋结构,已被证明是醛和酮加成反应的关键活性物质。根据(S)-4的袋结构和袋大小合理化了有关有机金属试剂与有机羰基加成反应的机理和立体化学见解。
MgBr<sub>2</sub>-promoted enantioselective aryl addition of ArTi(O<sup>i</sup>Pr)<sub>3</sub> to ketones catalyzed by a titanium(<scp>iv</scp>) catalyst of N,N′-sulfonylated (1R,2R)-cyclohexane-1,2-diamine
作者:Chao-Chi Shu、Shuangliu Zhou、Han-Mou Gau
DOI:10.1039/c5ra18871g
日期:——
MgBr2-promoted asymmetric addition of ArTi(OiPr)3 to ketonescatalyzed by a titanium catalyst of N,N′-sulfonylated (1R,2R)-cyclohexane-1,2-diamines is reported, and results showed that the chiral N,N′-sulfonylated cyclohexane-1,2-diamines with electron-withdrawing groups could effectively catalyze asymmetric addition of ArTi(OiPr)3 to ketones to afford desired tertiary alcohols in good yields with
据报道,MgBr 2促进了N,N'-磺酰化(1 R,2 R)-环己烷-1,2-二胺的钛催化剂催化的酮类化合物向酮中不对称地添加ArTi(O i Pr)3,结果表明:具有吸电子基团的手性N,N'-磺酰化环己烷-1,2-二胺可以有效催化不对称地将ArTi(O i Pr)3加到酮上,以高收率提供所需的叔醇,并具有良好的对映选择性。到95%ee。
Asymmetric addition of Grignard reagents to ketones: culmination of the ligand-mediated methodology allows modular construction of chiral tertiary alcohols
作者:Claudio Monasterolo、Ryan O'Gara、Saranna E. Kavanagh、Sadbh E. Byrne、Bartosz Bieszczad、Orla Murray、Michael Wiesinger、Rebecca A. Lynch、Kirill Nikitin、Declan G. Gilheany
DOI:10.1039/d1sc06350b
日期:——
A new class of biaryl chiral ligands derived from 1,2-diaminocyclohexane (1,2-DACH) has been designed to enable the asymmetric addition of aliphatic and, for the first time, aromatic Grignard reagents to ketones for the preparation of highly enantioenriched tertiary alcohols (up to 95% ee). The newly developed ligands L12 and L12′ together with the previously reported L0 and L0′ define a set of complementary
一种新的衍生自 1,2-二氨基环己烷 (1,2-DACH) 的联芳基手性配体已被设计用于将脂肪族和芳香族格氏试剂不对称加成到酮中,以制备高度对映体富集的叔酒精(高达 95% ee)。新开发的配体L12和L12'以及先前报道的L0和L0'定义了一组互补的手性启动子,它提供了对各种结构多样的非外消旋叔醇的模块化结构的访问,具有挑战性的季立体中心。目前的进展通过将范围扩展到芳族有机镁试剂来完成我们的不对称格氏方法,同时由于改进的合成路线可以直接获得手性配体而促进其在有机合成中的实施。该方法的合成效用已通过通过中间体 ( R ) -3a开发一种新型的、高度对映选择性的正式合成抗组胺药 API clemastine 得到证明. 利用格氏合成提供的 3-断开方法的力量,( R )- 3a与配体 ( R , R )- L12以 94% 的 ee 获得。本文描述的工作标志着我们为手性叔醇的不对称格氏合成建
Highly Enantioselective Aryl Additions of [AlAr3(thf)] to Ketones Catalyzed by a Titanium(IV) Catalyst of (S)-Binol