150927-39-2

Upstream product

• 2550-26-7 4-Phenyl-2-butanone 
• 557-20-0 diethylzinc 
• 910213-22-8 (R)-2-hydroxy-2-methyl-4-phenylbutyl p-toluenesulfonate 
• 75-16-1 methylmagnesium bromide 
• 6683-51-8 2-methyl-4-phenyl-1-butene 
• 76-09-5 2,3-dimethyl-2,3-butane diol 
• 82954-89-0 ethylboronic acid pinacol ester 
• 925-90-6 ethylmagnesium bromide 
• 73183-34-3 bis(pinacol)diborane 

Downstream Products

• 902523-69-7 (S)-1-ethyl-1-methyl-3-phenylpropyl diphenylphosphinite 
• 910213-17-1 (R)-3-methyl-1-phenylpentan-3-yl isocyanide 
• 925893-07-8 (R)-3-methyl-1-phenylpentan-3-ylamine 
• 925665-88-9 (R)-(3-azido-3-methylpentyl)benzene 

Relevant academic research and scientific papers

Synthesis of enantioenriched tertiary boronic esters by the lithiation/borylation of secondary alkyl benzoates

Simple, secondary 2,4,6-triisopropyl benzoates (TIB esters) and secondary dialkyl N,N-diisopropyl carbamates have been reported to be resistant to deprotonation by strong bases. We have found that the combination of sBuLi (1.6 equiv) and TMEDA (6 equiv) in CPME at -60 C enables deprotonation of unactivated secondary dialkyl TIB esters, but not the carbamates. These carbanions were reacted with a range of neopentyl boronic esters which, after 1,2-metalate rearrangement and oxidation, gave a range of tertiary alcohols in high yield and universally high er. Further functional group transformations of the tertiary boronic esters were demonstrated (conversion to quaternary centers, C-tertiary amines) together with application of the methodology to the synthesis of the simplest unbranched hydrocarbon bearing a quaternary center, (R)-4-ethyl-4-methyloctane, validating the synthetic utility of the methodology.

Harnessing the Power of the Asymmetric Grignard Synthesis of Tertiary Alcohols: Ligand Development and Improved Scope Exemplified by One-Step Gossonorol Synthesis

A series of N-substituted cyclohexyldiaminophenolic ligands for the asymmetric Grignard synthesis of tertiary alcohols is reported. The 2,5-dimethylpyrrole-decorated ligand led to improved enantioselectivities and broadened the scope of the methodology. As an exemplar, we report an unprecedented highly selective one-step synthesis of gossonorol in 93% ee, also constituting the shortest formal syntheses of natural products boivinianin B and yingzhaosu C.

Synthesis of Secondary and Tertiary Alkyl Boronic Esters by gem-Carboborylation: Carbonyl Compounds as Bis(electrophile) Equivalents

An unprecedent gem-carboborylation of aldehydes and ketones provides access to various secondary and tertiary alkyl boronic esters. The addition of B2pin2 to a carbonyl compound generates α-oxyl-substituted alkyl boron species. Organ

Asymmetric Grignard Synthesis of Tertiary Alcohols through Rational Ligand Design

A simple, general and practical method is reported for highly enantioselective construction of tertiary alcohols through 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 (>95:5 d.r.) of vitamin E.

Commercially available neat organozincs as highly reactive reagents for catalytic enantioselective addition to ketones and aldehydes under solvent free conditions

Neat Et2Zn, Ph2Zn, and highly concentrated Me 2Zn 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 solvent free or highly concentrated conditions without Ti(Oi-Pr)4 as a conventional activator of organozinc reagents. The desired optically active tertiary and secondary alcohols were obtained in good yield with high enantioselectivity when compared to the conventional solvent-use conditions. From the viewpoint of ecological and environmental reasons in green chemistry, this catalysis would be practical for not only academic but also industrial use.

Cyanation of alcohols with diethyl cyanophosphonate and 2,6-dimethyl-1,4-benzoquinone by a new type of oxidation-reduction condensation

Cyanation of various alcohols by a new type of oxidation-reduction condensation is described. Primary alkyl diphenylphosphinites, 2,6-dimethyl-1,4-benzoquinone (DMBQ), and diethyl cyanophosphonate gave the corresponding nitriles in high yields. During the above experiment on cyanation of 4-phenylbutan-2-ol, the unexpected formation of a mixture of nitrile and isocyanide was observed. After careful examination of the reaction conditions, selective synthesis of isocyanides from secondary alcohols was successfully accomplished by the use of zinc oxide (ZnO) as an additive. Reaction of tertiary alcohols provided the corresponding isocyanides exclusively in the absence of an additive. Cyanation of optically active alcohols was tried in order to clarify the stereochemistry of this reaction, and the reaction was thus proved to proceed with the inversion of configuration.

Catalytic asymmetric addition of alkylzinc and functionalized alkylzinc reagents to ketones

(Chemical Equation Presented) We describe our full report of the catalytic asymmetric addition of simple and functionalized dialkylzinc reagents to a broad range of saturated ketones and enones. The functionalized organozinc reagents contain esters, silyl

CATALYSTS, METHODS FOR MAKING SAID CATALYSTS, AND METHODS FOR MAKING CHIRAL COMPOUNDS WITH HIGH ENANTIOSELECTIVITY

The present invention relates to compounds useful as catalysts in asymmetric synthesis of chiral compounds, methods for the synthesis of said catalysts, and methods for synthesizing chiral compounds with high enantioselectivity.

A practical catalytic asymmetric addition of alkyl groups to ketones

Many catalysts will promote the asymmetric addition of alkylzinc reagents to aldehydes. In contrast, there are no reports of additions to ketones that are both general and highly enantioselective. We describe herein a practical catalytic asymmetric additi