Commercially available neat organozincs as highly reactive reagents for catalytic enantioselective addition to ketones and aldehydes under solvent free conditions
作者:Manabu Hatano、Tomokazu Mizuno、Kazuaki Ishihara
DOI:10.1016/j.tet.2011.02.042
日期:2011.6
Ph2Zn, and highly concentrated Me2Zn are highly reactive organozinc reagents, which are commercially available in bulk quantities. We here report a catalytic enantioselective Et2Zn, Ph2Zn, and Me2Zn addition to ketones and aldehydes under solventfree or highly concentrated conditions without Ti(Oi-Pr)4 as a conventional activator of organozinc reagents. The desired optically active tertiary and secondary
A practical and useful, catalyticenantioselective method has been developed for the synthesis of tertiary diaryl and aryl heteroaryl carbinols starting from commercially available aromatic ketones and aryl or heteroaryl bromides. In this method, organotitanium reagents are generated in situ from the bromides by lithiation with nBuLi followed by transmetallation of the resulting organolithiums with
已经开发了一种实用且有用的催化对映选择性方法,用于从可商购的芳族酮和芳基或杂芳基溴化物开始合成叔二芳基和芳基杂芳基甲醇。在该方法中,通过用n BuLi锂化从溴化物中原位生成有机钛试剂,然后用ClTi(O i Pr)3对所得的有机锂进行金属转移。在(R)-3-(3,5-双三氟甲基苯基)-1,1'-联-2-萘酚(BTFP-BINOL)以高对映选择性和高收率提供了相应的叔醇。反应也可以从呋喃和2-噻吩基锂开始。该方法操作简单,可在10 mmol规模下进行而没有任何困难。
Catalytic Enantioselective Addition of Aryl Grignard Reagents to Ketones
The authors acknowledge financial support from the Spanish Ministerio de Ciencia y Tecnologia (MCYT) (project numbers CTQ2007-65218/BQU and CTQ2011-24151), Consolider Ingenio 2010 (grant number CSD2007-00006), and Generalitat Valenciana (G. V. PROMETEO/2009/039 and FEDER). B. M. thanks the European Commision for a Marie Curie Career Integration Grant. E. F.-M. thanks the Ministerio de Educacion y Ciencia
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。